10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2018

¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number 001-37532

IBERIABANK Corporation

(Exact name of registrant as specified in its charter)

Louisiana	72-1280718
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

200 West Congress Street
Lafayette, Louisiana	70501
(Address of principal executive office)	(Zip Code)

(337) 521-4003

(Registrant’s telephone number, including area code)

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the Registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large Accelerated Filer	x	Accelerated Filer	¨
Non-accelerated Filer	¨	Smaller Reporting Company	¨
		Emerging Growth Company	¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

At April 30, 2018, the Registrant had 56,648,939 shares of common stock, $1.00 par value, which were issued and outstanding.

IBERIABANK CORPORATION AND SUBSIDIARIES

TABLE OF CONTENTS

	Page
Part I. Financial Information
Item 1.       Financial Statements (unaudited)
Consolidated Balance Sheets as of March 31, 2018 and December 31, 2017	4
Consolidated Statements of Comprehensive Income for the three months ended March 31, 2018 and 2017	5
Consolidated Statements of Shareholders’ Equity for the three months ended March 31, 2018 and 2017	7
Consolidated Statements of Cash Flows for the three months ended March 31, 2018 and 2017	8
Notes to Unaudited Consolidated Financial Statements	10
Item 2.        Management’s Discussion and Analysis of Financial Condition and Results of Operations	54
Item 3.       Quantitative and Qualitative Disclosures About Market Risk	81
Item 4.       Controls and Procedures	81
Part II. Other Information	82
Item 1.       Legal Proceedings	82
Item 1A.     Risk Factors	82
Item 2.       Unregistered Sales of Equity Securities and Use of Proceeds	83
Item 3.       Defaults Upon Senior Securities	83
Item 4.       Mine Safety Disclosures	83
Item 5.       Other Information	83
Item 6.       Exhibits	84
Signatures	85

3

Part I. FINANCIAL INFORMATION

Item 1. Financial Statements

IBERIABANK CORPORATION AND SUBSIDIARIES

Consolidated Balance Sheets

	(unaudited)
(Dollars in thousands, except share data)	March 31, 2018			December 31, 2017
Assets
Cash and due from banks	$	253,527		$	319,156
Interest-bearing deposits in banks	310,565			306,568
Total cash and cash equivalents	564,092			625,724
Securities available for sale, at fair value	4,542,486			4,590,062
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	224,241			227,318
Mortgage loans held for sale, at fair value	110,348			134,916
Loans and leases, net of unearned income	21,706,090			20,078,181
Allowance for loan and lease losses	(144,527		)	(140,891		)
Loans and leases, net	21,561,563			19,937,290
Premises and equipment, net	329,454			331,413
Goodwill	1,236,169			1,188,902
Other intangible assets	102,404			88,562
Other assets	801,880			779,942
Total Assets	$	29,472,637		$	27,904,129
Liabilities
Deposits:
Non-interest-bearing	$	6,595,495		$	6,209,925
Interest-bearing	16,375,697			15,256,792
Total deposits	22,971,192			21,466,717
Short-term borrowings	900,496			991,297
Long-term debt	1,449,302			1,495,835
Other liabilities	250,740			253,489
Total Liabilities	25,571,730			24,207,338
Shareholders’ Equity
Preferred stock, $1 par value - 5,000,000 shares authorized
Non-cumulative perpetual, liquidation preference $10,000 per share; 13,750 and 13,750 shares issued and outstanding, respectively, including related surplus	132,097			132,097
Common stock, $1 par value - 100,000,000 shares authorized; 56,778,841 and 53,872,272 shares issued and outstanding, respectively	56,779			53,872
Additional paid-in capital	3,001,389			2,787,484
Retained earnings	807,325			769,226
Accumulated other comprehensive income (loss)	(96,683		)	(45,888		)
Total Shareholders’ Equity	3,900,907			3,696,791
Total Liabilities and Shareholders’ Equity	$	29,472,637		$	27,904,129

The accompanying Notes are an integral part of these Consolidated Financial Statements.

4

IBERIABANK CORPORATION AND SUBSIDIARIES

Consolidated Statements of Comprehensive Income

(unaudited)

	Three Months Ended March 31,
(Dollars in thousands, except per share data)	2018			2017
Interest and Dividend Income
Loans, including fees	$	238,069		$	168,976
Mortgage loans held for sale, including fees	1,154			971
Investment securities:
Taxable interest	25,328			17,864
Tax-exempt interest	2,766			2,063
Other	3,226			2,659
Total interest and dividend income	270,543			192,533
Interest Expense
Deposits:
NOW and MMDA	21,228			11,100
Savings	432			320
Time deposits	6,584			4,638
Short-term borrowings	2,524			277
Long-term debt	6,886			3,380
Total interest expense	37,654			19,715
Net interest income	232,889			172,818
Provision for loan and lease losses	7,986			6,154
Net interest income after provision for loan and lease losses	224,903			166,664
Non-interest Income
Mortgage income	9,595			14,115
Service charges on deposit accounts	12,908			11,153
Title revenue	5,027			4,741
Broker commissions	2,221			2,547
ATM/debit card fee income	2,633			2,483
Credit card and merchant-related income	2,907			2,298
Trust department income	3,426			1,912
Income from bank owned life insurance	1,282			1,311
Gain (loss) on sale of available for sale securities	(59		)	—
Other non-interest income	4,626			4,564
Total non-interest income	44,566			45,124
Non-interest Expense
Salaries and employee benefits	104,586			81,853
Net occupancy and equipment	20,047			16,021
Communication and delivery	3,902			3,044
Marketing and business development	4,752			3,424
Data processing	12,393			6,362
Professional services	7,391			5,335
Credit and other loan related expense	4,618			4,526
Insurance	7,105			4,529
Travel and entertainment	3,237			2,484
Amortization of acquisition intangibles	5,102			1,770
Errors, fines, and losses	8,757			2,658
Other non-interest expense	6,406			6,790
Total non-interest expense	188,296			138,796
Income before income tax expense	81,173			72,992
Income tax expense	17,552			22,519
Net Income	63,621			50,473
Less: Preferred stock dividends	3,598			3,599
Net Income Available to Common Shareholders	$	60,023		$	46,874

5

Income available to common shareholders - basic	$	60,023		$	46,874
Less: Earnings allocated to unvested restricted stock	639			346
Earnings allocated to common shareholders	$	59,384		$	46,528
Earnings per common share - Basic	$	1.11		$	1.01
Earnings per common share - Diluted	1.10			1.00
Cash dividends declared per common share	0.38			0.36
Comprehensive Income
Net Income	$	63,621		$	50,473
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during the period (net of tax effects of $14,223 and $2,421, respectively)	(53,506		)	4,496
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $13 and $0, respectively)	(46		)	—
Unrealized gains (losses) on securities, net of tax	(53,460		)	4,496
Fair value of derivative instruments designated as cash flow hedges:
Change in fair value of derivative instruments designated as cash flow hedges during the period (net of tax effects of $678 and $39, respectively)	2,549			73
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $31 and $24, respectively)	(116		)	(45		)
Fair value of derivative instruments designated as cash flow hedges, net of tax	2,665			118
Other comprehensive income (loss), net of tax	(50,795		)	4,614
Comprehensive income	$	12,826		$	55,087

The accompanying Notes are an integral part of these Consolidated Financial Statements.

6

IBERIABANK CORPORATION AND SUBSIDIARIES

Consolidated Statements of Shareholders’ Equity

(unaudited)

							Additional Paid in Capital			Retained Earnings			Accumulated Other Comprehensive Income (Loss)			Total
	Preferred Stock			Common Stock
(In thousands, except share and per share data)	Shares	Amount		Shares	Amount
Balance, December 31, 2016	13,750	$	132,097	44,795,386	$	44,795	$	2,084,446		$	704,391		$	(26,035	)	$	2,939,694
Net income	—	—		—	—		—			50,473			—			50,473
Other comprehensive income/(loss)	—	—		—	—		—			—			4,614			4,614
Cash dividends declared, $0.36 per share	—	—		—	—		—			(18,271		)	—			(18,271		)
Preferred stock dividends	—	—		—	—		—			(3,599		)	—			(3,599		)
Common stock issued under incentive plans, net of shares surrendered in payment, including tax benefit	—	—		74,522	75		(3,926		)	—			—			(3,851		)
Common stock issued	—	—		6,100,000	6,100		479,094			—			—			485,194
Share-based compensation cost	—	—		—	—		3,721			—			—			3,721
Balance, March 31, 2017	13,750	$	132,097	50,969,908	$	50,970	$	2,563,335		$	732,994		$	(21,421	)	$	3,457,975
Balance, December 31, 2017	13,750	$	132,097	53,872,272	$	53,872	$	2,787,484		$	769,226		$	(45,888	)	$	3,696,791
Cumulative-effect adjustment due to the adoption of ASU 2016-01 (1)	—	—		—	—		—			(345		)	—			(345		)
Net income	—	—		—	—		—			63,621			—			63,621
Other comprehensive income/(loss)	—	—		—	—		—			—			(50,795		)	(50,795		)
Cash dividends declared, $0.38 per share	—	—		—	—		—			(21,579		)	—			(21,579		)
Preferred stock dividends	—	—		—	—		—			(3,598		)	—			(3,598		)
Common stock issued under incentive plans, net of shares surrendered in payment	—	—		118,796	119		(2,700		)	—			—			(2,581		)
Common stock issued for acquisitions	—	—		2,787,773	2,788		211,871			—			—			214,659
Share-based compensation cost	—	—		—	—		4,734			—			—			4,734
Balance, March 31, 2018	13,750	$	132,097	56,778,841	$	56,779	$	3,001,389		$	807,325		$	(96,683	)	$	3,900,907
(1) Cumulative-effect adjustment to beginning retained earnings for fair value adjustments related to the reclassification of certain equity investments in accordance with ASU 2016-01, adopted as of January 1, 2018.

The accompanying Notes are an integral part of these Consolidated Financial Statements.

7

IBERIABANK CORPORATION AND SUBSIDIARIES

Consolidated Statements of Cash Flows

(unaudited)

	For the Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Cash Flows from Operating Activities
Net income	$	63,621		$	50,473
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion, including amortization of purchase accounting adjustments and market value adjustments	(309		)	1,646
Provision for loan and lease losses	7,986			6,154
Share-based compensation cost - equity awards	4,734			3,721
Loss/(gain) on sale of OREO and long-lived assets, net of impairment	670			(746		)
Loss/(gain) on sale of available for sale securities	59			—
Expense/(benefit) for deferred income taxes	10,992			(10,565		)
Originations of mortgage loans held for sale	(336,400		)	(393,924		)
Proceeds from sales of mortgage loans held for sale	367,487			440,337
Realized and unrealized (gain)/loss on mortgage loans held for sale, net	(9,320		)	(13,689		)
Other operating activities, net	(13,113		)	(20,933		)
Net Cash Provided by Operating Activities	96,407			62,474
Cash Flows from Investing Activities
Proceeds from maturities, prepayments and calls of available for sale securities	149,987			113,940
Purchases of available for sale securities, net of available for sale securities acquired	(194,543		)	(491,055		)
Proceeds from maturities, prepayments and calls of held to maturity securities	2,288			2,968
Purchases of equity securities, net of equity securities acquired	(2,452		)	(200		)
Proceeds from sales of equity securities	61,038			—
Increase in loans, net of loans acquired	(145,201		)	(60,609		)
Proceeds from sales of premises and equipment	1,408			7
Purchases of premises and equipment, net of premises and equipment acquired	(5,798		)	(2,761		)
Proceeds from dispositions of OREO	5,318			4,374
Cash paid for additional investment in tax credit entities	(750		)	(795		)
Cash received for acquisition of a business, net of cash paid	99,312			—
Other investing activities, net	(745		)	6,327
Net Cash Used in Investing Activities	(30,138		)	(427,804		)
Cash Flows from Financing Activities
Increase/(decrease) in deposits, net of deposits acquired	440,470			(95,916		)
Net change in short-term borrowings	(90,802		)	(60,440		)
Proceeds from long-term debt, net of long-term debt acquired	200,227			—
Repayments of long-term debt	(651,684		)	(622		)
Cash dividends paid on common stock	(19,933		)	(16,126		)
Cash dividends paid on preferred stock	(3,598		)	(3,599		)
Net share-based compensation stock transactions	(2,581		)	(4,169		)
Net proceeds from issuance of common stock	—			485,194
Net Cash Used in Financing Activities	(127,901		)	304,322
Net Increase (Decrease) In Cash and Cash Equivalents	(61,632		)	(61,008		)
Cash and Cash Equivalents at Beginning of Period	625,724			1,362,126
Cash and Cash Equivalents at End of Period	$	564,092		$	1,301,118
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	$	1,757		$	2,733

8

Common stock issued in acquisitions	$	214,659	$	—
Supplemental Disclosures
Cash paid for:
Interest on deposits and borrowings	$	37,035	$	19,850
Income taxes, net	$	101	$	39,609

The accompanying Notes are an integral part of these Consolidated Financial Statements.

9

IBERIABANK CORPORATION AND SUBSIDIARIES

Notes to Consolidated Financial Statements

NOTE 1 - BASIS OF PRESENTATION

General

IBERIABANK Corporation is a regional financial holding company with offices in Louisiana, Arkansas, Tennessee, Alabama, Texas, Florida, Georgia, South Carolina, North Carolina, and New York offering commercial, private banking, consumer, small business, wealth and trust management, retail brokerage, mortgage, and title insurance services. The consolidated financial statements include the accounts of the Company and its subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Certain amounts reported in prior periods have been reclassified to conform to the current period presentation. These reclassifications did not have a material effect on previously reported consolidated financial statements.

The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all information or footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal and recurring items, necessary for a fair presentation of the consolidated financial statements have been made. These interim financial statements should be read in conjunction with the audited consolidated financial statements and footnote disclosures for the Company previously filed with the SEC in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Operating results for the period ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018.

When we refer to the “Company,” “we,” “our,” or “us” in this Report, we mean IBERIABANK Corporation and subsidiaries (consolidated). When we refer to the “Parent,” we mean IBERIABANK Corporation. See the Glossary of Defined Terms at the end of this Report for terms used throughout this Report.

Concentrations of Credit Risk

Most of the Company’s business activity is with customers located in the southeastern United States. The Company’s lending activity is concentrated in its market areas within those states. The Company has emphasized originations of commercial loans and private banking loans, defined as loans to higher net worth clients. Repayments on loans are expected to come from cash flows of the borrower and/or guarantor. Losses on secured loans are limited by the net realizable value of the collateral upon default of the borrowers and guarantor support. The Company believes it does not have any excessive concentrations to any one industry, loan type, or customer.

10

NOTE 2 - RECENT ACCOUNTING PRONOUNCEMENTS

Pronouncements adopted during the three months ended March 31, 2018:

ASU No. 2014-09

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which implements a common revenue standard and clarifies the principles used for recognizing revenue. The amendments in the ASU clarify that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.

Revenue from Contracts with Customers

The majority of the Company’s income streams (e.g., interest and dividend income and mortgage income) are accounted for in accordance with GAAP literature outside the scope of ASC 606, Revenue from Contracts with Customers. Details regarding income recognition for interest and non-interest streams can be found throughout the Company’s 2017 10-K (including Note 1 - Summary of Significant Accounting Policies). Impairment losses recognized against certain receivables (e.g., NSF fees) and capitalized costs (e.g., sales commissions) associated with contracts within the scope of ASC 606 are immaterial.

Non-interest income from service charges on deposit accounts, broker commissions, ATM/debit card fee income, credit card and merchant-related income (e.g., interchange fees), and transactional income from traditional banking services (part of other non-interest income) are the significant income streams within the scope of ASC 606 associated with the IBERIABANK reportable segment. Non-interest income from title revenue is associated with the LTC reportable segment.

Recognition of Revenue from Contracts with Customers

The Company enters into various contracts with customers to provide traditional banking services, including asset management, on a routine basis. The Company’s performance obligations are generally service-related and provided on a daily or monthly basis. The Company does not typically have performance obligations which extend beyond a reporting period. The performance obligations are generally satisfied upon completion of service (i.e., as services are rendered) and the fees are collected at such time, or shortly thereafter. The fees are readily determinable and allocated individually to each service. It is not typical for contracts to require significant judgment to determine the transaction price. Some contracts contain variable consideration; however, the variable consideration is generally constrained (not estimable) as it is based on the occurrence or nonoccurence of a contingent event (or another constraint in some circumstances). The Company generally records the variable consideration when the contingent event occurs and the fee is determinable.

The Company provides some services for customers in which it acts in an agent capacity, but generally acts in a principal capacity. Payment terms and conditions vary slightly amongst services; however, amounts are generally invoiced and due or collected by the Company within 30 days, although some fees may be prepaid. The Company bills the customer periodically as performance obligations are satisfied for most services. Therefore, revenue for services provided is generally recognized in the amount invoiced (except in circumstances of prepayment) as that amount corresponds directly to the value of the Company’s performance. In the normal course of business, the Company does not generally grant refunds for services provided. As such, the Company does not establish provisions for estimated returns.

Title revenue associated with services provided by LTC, as well as broker commissions, ATM/debit card fee income, credit card and merchant-related income (e.g., interchange fees), and transactional fees from traditional banking services generated within IBERIABANK are generally recognized at the point-in-time the services are provided. The Company has determined this recognition to be appropriate as, upon completion of services, the Company has completed its performance obligations, has a present right to payment (or has collected the cash), and the customer is able to obtain (or has obtained) substantially all of the benefits from the performance obligation (i.e., the provided services). Revenues from service charges on deposit accounts are recognized at the end of the monthly service period (e.g., account service charges) or the date the performance obligation is satisfied (e.g., NSF, stop payment, wire transfer, etc.), except for deposit account services performed by Treasury Management which are recognized on a monthly basis, as these services are performed over that time. Asset management fees (e.g., trust fees) are generally recognized at the end of the monthly service period, but fees are not collected until the beginning of the subsequent month, although some contracts may have quarterly terms and/or be prepaid. NSF fees which are not initially paid are subsequently recorded as “loans” (along with the overdraft balance) and remain classified as such until the amount is paid or charged-off (generally after 60 days).

11

Adoption of ASC 606

The Company adopted ASC 606 as of January 1, 2018 for all contracts as of the effective date. Prior period amounts have been reclassified to conform to current guidance requirements related to the net presentation of certain costs associated with interchange fees and rewards programs. The reclassification of prior period amounts reduced non-interest income and non-interest expense by an immaterial amount (approximately $2.2 million for the three months ended March 31, 2017) and had no impact on net income. There was no cumulative adjustment made to opening retained earnings as of January 1, 2018.

ASU No. 2016-01

In January 2016, the FASB issued ASU No. 2016-01, Financial Statements - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, which impacts how the Company measures certain equity investments and discloses and presents certain financial instruments through the application of the “exit price” notion.

The Company adopted the amendments beginning January 1, 2018. Under the new guidance, equity investments can no longer be classified as trading or available for sale (AFS), and related unrealized holding gains and losses can no longer be recognized in OCI. Per the ASU, such equity investments should be measured at fair value, with adjustments recognized in earnings at the end of each reporting period. As such, the Company reclassified its portfolio of equity investments (approximately $9.8 million at March 31, 2018) previously classified as AFS investment securities to “other assets.” As these equity investments were previously measured at fair value, implementation of the ASU did not impact the Company’s valuation method. In accordance with the ASU, the cumulative-effect adjustment from AOCI to retained earnings for previously recorded fair value adjustments related to these equity investments at adoption was insignificant.

The Company elected the practical expedient measurement alternative to prospectively account for other equity investments that do not have readily determinable fair values at cost less impairment plus or minus observable price changes in orderly transactions for an identical or similar investment of the same issuer. These investments are immaterial overall and are classified within “other assets” on the Company’s consolidated balance sheets.

The Company also modified its fair value methodology for loans measured at amortized cost whose fair values were previously disclosed using an “entry price” methodology to an “exit price” methodology, in accordance with the ASU. The Company’s “exit price” methodology estimates the fair value of these loans based on the present value of the future cash flows using the interest rate that would be charged for a similar loan to a borrower with similar risk at the indicated balance sheet date, adjusted for a liquidity discount based on the estimated time period to complete a sale transaction with a market participant. This change in methodology solely impacted the Company’s disclosures, and had no impact to the Company’s consolidated financial statements.

ASU No. 2016-15

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (ASC 230): Classification of Certain Cash Receipts and Cash Payments, in order to reduce current diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows.

The Company retrospectively adopted the amendments effective January 1, 2018. The adoption of these amendments did not impact the Company’s consolidated statements of cash flows.

ASU No. 2017-12

In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities, which amends the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements and enhance the transparency and understandability of hedge results.

The Company elected to early adopt the amendments effective January 1, 2018. The modified-retrospective adoption of the amendments did not impact the Company’s consolidated financial statements in the current or prior periods.

12

Pronouncements issued but not yet adopted:

ASU No. 2016-02

In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842). A significant amendment to existing GAAP from this ASU is the recognition of lease assets (i.e., right of use assets) and liabilities on the balance sheet for leases that are classified as operating leases by lessees. The lessor model remains similar to the current accounting model in existing GAAP. Additional amendments include, but are not limited to, the elimination of leveraged leases; modification to the definition of a lease; amendments on sale and leaseback transactions; and disclosure of additional quantitative and qualitative information.

ASU 2016-02 will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. Lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company will adopt the amendments on January 1, 2019.

The Company occupies certain banking offices and equipment under operating lease agreements, which currently are not recognized on the consolidated balance sheets. Based on the Company’s preliminary analysis of its current portfolio, the impact to the Company’s consolidated balance sheets is estimated to result in less than a 1% increase in assets and liabilities. The Company is also currently assessing the practical expedients it may elect at adoption, the final determination of the incremental borrowing rate, and the impact to regulatory capital ratios, amongst other matters associated with the ASU.

The adjustment to retained earnings is not expected to be significant based on the transition guidance associated with current sale-leaseback agreements. The Company also anticipates additional disclosures to be provided at adoption.

ASU No. 2016-13

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments. The amendments introduce an impairment model that is based on expected credit losses (“ECL”), rather than incurred losses, to estimate credit losses on certain types of financial instruments (e.g., loans and held-to-maturity securities), including certain off-balance sheet financial instruments (e.g., loan commitments). The measurement of ECL should consider historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments, over the contractual term. Financial instruments with similar risk characteristics may be grouped together when estimating ECL.

The ASU also amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset through the use of an allowance to record estimated credit losses (and subsequent recoveries). Non-credit related losses will continue to be recognized through OCI.

In addition, the amendments provide for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination. The initial estimate of expected credit losses would be recognized through an ALLL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition.

ASU 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods. The amendments will be applied through a modified-retrospective approach, resulting in a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. A prospective transition approach is required for debt securities for which OTTI had been recognized before the effective date. Amounts previously recognized in AOCI as of the date of adoption that relate to improvements in cash flows expected to be collected should continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption should be recorded in earnings when received.

The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements; however, the Company has engaged third-party consultants to assist with the ASU and has developed an implementation plan.

13

NOTE 3 –ACQUISITION ACTIVITY

The acquisitions discussed below qualify as business combinations. The Company accounts for business combinations under the acquisition method in accordance with ASC Topic 805, Business Combinations. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017, for further discussion of the Company's accounting for business combinations.

2018 Acquisitions

Acquisition of Gibraltar

The Company completed the acquisition of Gibraltar Private Bank & Trust Co. ("Gibraltar") on March 23, 2018. The acquisition added $1.5 billion in loans and $1.1 billion in deposits, based on preliminary purchase accounting adjustments. Gibraltar operated eight offices in total, with seven located in the Florida metropolitan statistical areas of Miami, Key West, and Naples and one in New York City.

Under the terms of the Agreement and Plan of Merger, Gibraltar common shareholders received 1.9749 shares of IBERIABANK Corporation common stock for each outstanding share of Gibraltar common stock. Based on the Company's closing common stock price of $77.00 per share on March 23, 2018, the aggregate value of the acquisition consideration paid at the time of closing was approximately $214.7 million.

During the first quarter of 2018, the Company recorded preliminary purchase price allocations related to Gibraltar, which resulted in goodwill of $42.5 million. The following table summarizes the consideration paid for Gibraltar's net assets and the preliminary fair value estimates of the identifiable assets acquired and liabilities assumed as of the acquisition date.

(Dollars in thousands)	Number of Shares	Amount
Equity consideration
Common stock issued	2,787,773	$	214,659
Total equity consideration		214,659
Non-equity consideration
Cash		7
Total consideration paid		214,666
Fair value of net assets assumed including identifiable intangible assets		172,136
Goodwill		$	42,530

(Dollars in thousands)	Gibraltar Fair Value (Preliminary)
Assets
Cash and cash equivalents	$	102,570
Investment securities	19,169
Equity securities	27,519
Loans	1,465,319
Core deposit intangible assets	18,529
Deferred tax asset, net	689
Other assets	14,382
Total assets acquired	$	1,648,177
Liabilities
Deposit liabilities	$	1,064,803
Long-term borrowings	405,107
Other liabilities	6,131
Total liabilities assumed	$	1,476,041

14

The following is a description of the methods used to determine the fair values of significant assets acquired and liabilities assumed presented above.

Cash and Cash Equivalents: The carrying amount of these assets is a reasonable estimate of fair value based on the short-term nature of these assets.

Investment Securities: Fair values for securities were based on quoted market prices from multiple bond dealers. The simple average of the prices received was used to calculate the adjustments.

Equity Securities: The carrying amount of these securities is a reasonable estimate of fair value based on the short-term nature of these assets.

Loans: Fair values for loans were based on a discounted cash flow methodology that considered factors including loan type, classification status, remaining term of the loan, fixed or variable interest rate, amortization status and current discount rates. The discount rates used for loans were based on current market rates for new originations of comparable loans and included adjustments for any liquidity concerns. The discount rate did not include an explicit factor for credit losses, as that was included as a reduction to the estimated cash flows.

Core Deposit Intangible Assets ("CDI"): The fair value for CDI was estimated based on a discounted cash flow methodology that gave appropriate consideration to expected customer attrition rates, net maintenance cost of the deposit base, alternative costs of funds, and the interest costs associated with the customer deposits. The CDI is being amortized over its estimated useful life of approximately ten years utilizing an accelerated method.

Deposit Liabilities: The fair values used for the demand and savings deposits by definition equal the amount payable on demand at the acquisition date. Fair values for time deposits were estimated using a discounted cash flow analysis, that applied interest rates currently being offered to the contractual interest rates on such time deposits.

Long-term Borrowings: The carrying amount of long-term borrowings at the acquisition date approximated fair value, as the Company immediately paid off the debt upon acquisition.

Acquisition of SolomonParks

On January 12, 2018, the Company's subsidiary, Lenders Title Company ("LTC"), acquired SolomonParks Title & Escrow, LLC ("SolomonParks"). Under the terms of the Agreement, LTC paid $3.3 million in cash to acquire eight title offices in the Nashville, Tennessee area, which resulted in goodwill of $3.4 million. In addition, the agreement provides for potential additional cash consideration based on gross revenues over a two-year period after the acquisition. The following table summarizes the preliminary fair value estimates of the identifiable assets acquired and liabilities assumed as of the acquisition date.

(Dollars in thousands)	SolomonParks Fair Value (Preliminary)
Assets
Premise and equipment, net	$	42
Non-compete agreement	156
Title Plant investment	15
Total assets acquired	$	213
Liabilities
Contingent consideration	$	343
Total liabilities assumed	$	343

Information regarding the preliminary allocation of goodwill recorded as a result of these acquisitions to the Company's reportable segments is provided in Note 7 "Goodwill and Other Intangible Assets." The goodwill recorded as a result of these acquisitions is not deductible for tax purposes.

15

2017 Acquisition

Acquisition of Sabadell United

The Company completed the acquisition of Sabadell United Bank, N.A. ("Sabadell United") from Banco de Sabadell, S.A. on July 31, 2017. The acquisition of Sabadell United constituted a business combination. Accordingly, assets acquired, liabilities assumed, and consideration exchanged were recorded at their estimated fair value on the acquisition date. The acquisition added $4.0 billion in loans and $4.4 billion in deposits after fair value adjustments. The acquisition expanded our presence in Southeast Florida adding 25 offices serving the Miami metropolitan area and three offices in Naples, Sarasota and Tampa.

Under the terms of the Stock Purchase Agreement, Banco de Sabadell, S.A. received $809.2 million in cash and 2,610,304 shares of IBERIABANK Corporation common stock in exchange for 100 percent of Sabadell United's common stock. The cash consideration was financed through two public common stock offerings completed on December 7, 2016, and March 7, 2017.

During the third quarter of 2017, the Company recorded preliminary purchase price allocations related to Sabadell United. Throughout the remainder of 2017 and the first quarter of 2018, the Company continued to analyze the valuations assigned to the acquired assets and liabilities assumed. Based on new information relating to events or circumstances existing at the acquisition date and revised valuations, the Company updated estimated fair values increasing goodwill by $1.4 million to $463.4 million during the first quarter of 2018. This increase is primarily a result of a change in the estimated fair value of the deferred tax asset. Asof March 31, 2018, the Company continues to review its fair value estimates and additional adjustments may be required.The following table summarizes the consideration paid for Sabadell United's net assets and the preliminary fair value estimates of identifiable assets acquired and liabilities assumed as of the acquisition date.

(Dollars in thousands)	Number of Shares	Amount
Equity consideration
Common stock issued	2,610,304	$	211,043
Total equity consideration		211,043
Non-equity consideration
Cash		809,159
Total consideration paid		1,020,202
Fair value of net assets assumed including identifiable intangible assets		556,799
Goodwill		$	463,403

(Dollars in thousands)	Sabadell United Fair Value (Preliminary)
Assets
Cash and cash equivalents	$	318,834
Investment securities	964,123
Loans	4,025,946
Core deposit intangible assets	66,600
Deferred tax asset, net	33,469
Other assets	89,745
Total assets acquired	$	5,498,717
Liabilities
Deposit liabilities	$	4,382,780
Short-term borrowings	520,539
Other liabilities	38,599
Total liabilities assumed	$	4,941,918

16

Information regarding the preliminary allocation of goodwill recorded as a result of the acquisition to the Company's reportable segments is provided in Note 7 "Goodwill and Other Intangible Assets." The goodwill recorded as a result of the acquisition is not deductible for tax purposes.

All measurement period adjustments made during the first three months of 2018 have been deemed insignificant individually and in the aggregate. The Company will finalize its valuation of the Sabadell United acquisition within the measurement period (i.e., no later than July 31, 2018). See Note 3, Acquisition Activity, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017, for a description of the methods used to determine the fair values of significant assets acquired and liabilities assumed presented above.

The Company's consolidated financial statements as of and for the period ended March 31, 2018 include the operating results of the acquired assets and liabilities assumed. Due to the system conversion of Sabadell United in October 2017 and subsequent streamlining and integration of the operating activities into those of the Company, historical reporting for the former Sabadell United operations is impracticable and thus disclosure of the revenue from the assets acquired and income before income taxes is impracticable for the period subsequent to acquisition.

The following table presents unaudited pro forma information as if the acquisition occurred on January 1, 2016 under the "Unaudited Pro Forma" column. The pro forma information does not necessarily reflect the results of operations that would have occurred had the Company acquired Sabadell United on January 1, 2016. Furthermore, cost savings and other business synergies related to the acquisition are not reflected in the pro forma amounts.

	Unaudited Pro Forma for
(Dollars in thousands)	Three months ended March 31, 2017
Net interest income	$	231,087
Non-interest income	54,755
Net income	43,562

This pro forma information combines the historical consolidated results of operations of IBERIABANK and Sabadell United for the periods presented and gives effect to the following non recurring adjustments:

Fair value adjustments: Pro forma adjustment to net interest income of $5.1 million for the three months ended March 31, 2017 to record estimated amortization of premiums and accretion of discounts on acquired loans, securities, and deposits.

Sabadell United accretion / amortization: Pro forma adjustment to net interest income of $318.5 thousand for the three months ended March 31, 2017 to eliminate Sabadell United's amortization of premiums and accretion of discounts on previously acquired loans, securities, FDIC indemnification asset, and deposits.

Sabadell United provision for loan losses: Pro forma adjustments were made to provision for loan losses of $1.6 million for the three months ended March 31, 2017 to eliminate the reversal (benefit) of Sabadell United's release of provision for loan losses and to account for the provision for loan losses on new loans originated during the period presented.

Amortization of acquired intangibles: Pro forma adjustment to non-interest expense of $1.5 million for the three months ended March 31, 2017 to record estimated amortization of acquired intangible assets.

Other adjustments: Pro forma results also include adjustments related to the removal of benefit from release of reserve for unfunded lending commitments, removal of FDIC clawback liability expense, adjustments to FDIC insurance and other regulatory assessment expenses and related income tax effects.

17

NOTE 4 – INVESTMENT SECURITIES

The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following:

	March 31, 2018
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	6,824	$	—	$	—		$	6,824
U.S. Government-sponsored enterprise obligations	41,001		11		(654		)	40,358
Obligations of state and political subdivisions	267,962		1,228		(4,156		)	265,034
Mortgage-backed securities	4,277,033		279		(121,215		)	4,156,097
Other securities	75,205		106		(1,138		)	74,173
Total securities available for sale	$	4,668,025	$	1,624	$	(127,163	)	$	4,542,486
Securities held to maturity:
Obligations of state and political subdivisions	$	204,404	$	726	$	(4,120	)	$	201,010
Mortgage-backed securities	19,837		35		(1,014		)	18,858
Total securities held to maturity	$	224,241	$	761	$	(5,134	)	$	219,868

	December 31, 2017
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	41,003	$	18	$	(406	)	$	40,615
Obligations of state and political subdivisions	271,451		4,246		(1,493		)	274,204
Mortgage-backed securities	4,221,472		1,461		(61,028		)	4,161,905
Other securities	114,005		247		(914		)	113,338
Total securities available for sale	$	4,647,931	$	5,972	$	(63,841	)	$	4,590,062
Securities held to maturity:
Obligations of state and political subdivisions	$	206,736	$	1,530	$	(275	)	$	207,991
Mortgage-backed securities	20,582		41		(650		)	19,973
Total securities held to maturity	$	227,318	$	1,571	$	(925	)	$	227,964

Securities with carrying values of $2.1 billion were pledged to secure public deposits and other borrowings at both March 31, 2018 and December 31, 2017.

18

Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, is as follows:

	March 31, 2018
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	—		$	693	$	—		$	—	$	—		$	693
U.S. Government-sponsored enterprise obligations	(419		)	29,580		(235		)	9,765		(654		)	39,345
Obligations of state and political subdivisions	(1,147		)	96,138		(3,009		)	66,404		(4,156		)	162,542
Mortgage-backed securities	(68,161		)	2,847,244		(53,054		)	1,191,233		(121,215		)	4,038,477
Other securities	(1,138		)	60,304		—			—		(1,138		)	60,304
Total securities available for sale	$	(70,865	)	$	3,033,959	$	(56,298	)	$	1,267,402	$	(127,163	)	$	4,301,361
Securities held to maturity:
Obligations of state and political subdivisions	$	(4,066	)	$	150,188	$	(54	)	$	2,976	$	(4,120	)	$	153,164
Mortgage-backed securities	(11		)	323		(1,003		)	18,187		(1,014		)	18,510
Total securities held to maturity	$	(4,077	)	$	150,511	$	(1,057	)	$	21,163	$	(5,134	)	$	171,674

	December 31, 2017
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	(254	)	$	29,744	$	(152	)	$	9,848	$	(406	)	$	39,592
Obligations of state and political subdivisions	(326		)	31,601		(1,167		)	68,609		(1,493		)	100,210
Mortgage-backed securities	(26,263		)	2,677,338		(34,765		)	1,226,058		(61,028		)	3,903,396
Other securities	(914		)	75,302		—			—		(914		)	75,302
Total securities available for sale	$	(27,757	)	$	2,813,985	$	(36,084	)	$	1,304,515	$	(63,841	)	$	4,118,500
Securities held to maturity:
Obligations of state and political subdivisions	$	(263	)	$	65,817	$	(12	)	$	3,031	$	(275	)	$	68,848
Mortgage-backed securities	(2		)	333		(648		)	19,269		(650		)	19,602
Total securities held to maturity	$	(265	)	$	66,150	$	(660	)	$	22,300	$	(925	)	$	88,450

The Company assessed the nature of the unrealized losses in its portfolio as of March 31, 2018 and December 31, 2017 to determine if there are losses that should be deemed other-than-temporary. In its analysis of these securities, management considered numerous factors to determine whether there were instances where the amortized cost basis of the debt securities would not be fully recoverable, including, but not limited to:

• The length of time and extent to which the estimated fair value of the securities was less than their amortized cost;

• Whether adverse conditions were present in the operations, geographic area, or industry of the issuer;

• The payment structure of the security, including scheduled interest and principal payments, including the issuer’s failures to make scheduled payments, if any, and the likelihood of failure to make scheduled payments in the future;

• Changes to the rating of the security by a rating agency; and

• Subsequent recoveries or additional declines in fair value after the balance sheet date.

19

Management believes it has considered these factors, as well as all relevant information available, when determining the expected future cash flows of the securities in question. In each instance, management has determined the cost basis of the securities would be fully recoverable. Management also has the intent to hold debt securities until their maturity or anticipated recovery if the security is classified as available for sale. In addition, management does not believe the Company will be required to sell debt securities before the anticipated recovery of the amortized cost basis of the security. As a result of the Company's analysis, no declines in the estimated fair value of the Company's investment securities were deemed to be other-than-temporary at March 31, 2018 or December 31, 2017.

At March 31, 2018, 635 debt securities had unrealized losses of 2.87% of the securities’ amortized cost basis. At December 31, 2017, 544 debt securities had unrealized losses of 1.52% of the securities’ amortized cost basis. The unrealized losses for each of the securities related to market interest rate changes and not credit concerns of the issuers. Additional information on securities that have been in a continuous loss position for over twelve months at March 31, 2018 and December 31, 2017 is presented in the following table.

(Dollars in thousands)	March 31, 2018		December 31, 2017
Number of securities:
Mortgage-backed securities	184		181
Obligations of state and political subdivisions	28		28
Other	1		1
	213		210
Amortized Cost Basis:
Mortgage-backed securities	$	1,263,477	$	1,280,739
Obligations of state and political subdivisions	72,443		72,820
Other	10,000		10,000
	$	1,345,920	$	1,363,559
Unrealized Loss:
Mortgage-backed securities	$	54,057	$	35,412
Obligations of state and political subdivisions	3,063		1,180
Other	235		152
	$	57,355	$	36,744

The securities noted above carry a rating of AA+/Aaa by S&P and Moody's.

The amortized cost and estimated fair value of investment securities by maturity at March 31, 2018 are presented in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Weighted average yields are calculated on the basis of the yield to maturity based on the amortized cost of each security.

	Securities Available for Sale						Securities Held to Maturity
(Dollars in thousands)	Weighted Average Yield		Amortized Cost		Estimated Fair Value		Weighted Average Yield		Amortized Cost		Estimated Fair Value
Within one year or less	2.06	%	$	6,667	$	6,670	3.04	%	$	1,445	$	1,448
One through five years	2.04		134,449		132,594		2.98		8,369		8,370
After five through ten years	2.36		887,796		868,090		2.66		45,690		45,450
Over ten years	2.38		3,639,113		3,535,132		2.56		168,737		164,600
	2.38	%	$	4,668,025	$	4,542,486	2.60	%	$	224,241	$	219,868

20

The following is a summary of realized gains and losses from the sale of securities classified as available for sale. Gains or losses on securities sold are recorded on the trade date, using the specific identification method.

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Realized gains	$	9		$	—
Realized losses	(68		)	—
	$	(59	)	$	—

In addition to the gains above, the Company realized certain gains on calls of securities held to maturity that were not significant to the consolidated financial statements.

Other Equity Securities

The Company accounts for the following securities at cost less impairment plus or minus any observable price changes, which approximates fair value, with the exception of CRA and Community Development Investment Funds, which are recorded at fair value. Other Equity Securities, which are presented in “other assets” on the consolidated balance sheets, are as follows:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Federal Home Loan Bank (FHLB) stock	$	90,561	$	95,171
Federal Reserve Bank (FRB) stock	79,191		79,191
CRA and Community Development Investment Funds	9,801		—
Other investments	9,705		3,008
	$	189,258	$	177,370

21

NOTE 5 – LOANS AND LEASES

Loans and leases consist of the following for the periods indicated:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Commercial loans and leases:
Real estate- construction	$	1,199,625	$	1,240,396
Real estate- owner-occupied	2,612,244		2,529,885
Real estate- non-owner-occupied	5,437,082		5,167,949
Commercial and industrial (1)	5,325,682		5,135,067
	14,574,633		14,073,297
Residential mortgage loans:	3,971,067		3,056,352
Consumer loans:
Home equity	2,421,186		2,292,275
Indirect automobile	50,671		62,693
Credit card	93,261		96,368
Other	595,272		497,196
	3,160,390		2,948,532
Total	$	21,706,090	$	20,078,181

⁽¹⁾  Includes equipment financing leases.

Net deferred loan origination fees were $31.4 million and $29.3 million at March 31, 2018 and December 31, 2017, respectively. Total net discount on the Company's loans was $158.1 million and $159.3 million at March 31, 2018 and December 31, 2017, respectively, of which $100.8 million and $94.7 million was related to non-impaired loans. Net loan discounts include preliminary discounts recorded on Sabadell United and Gibraltar loans, which are subject to change upon receipt of final fair value estimates during the respective measurement periods.

In addition to loans issued in the normal course of business, the Company considers overdrafts on customer deposit accounts to be loans and reclassifies these overdrafts as loans in its consolidated balance sheets. At March 31, 2018 and December 31, 2017, overdrafts of $7.3 million and $7.4 million, respectively, have been reclassified to loans.

Loans with carrying values of $6.8 billion and $6.6 billion were pledged as collateral for borrowings at March 31, 2018 and December 31, 2017, respectively.

22

Aging Analysis

The following tables provide an analysis of the aging of loans as of March 31, 2018 and December 31, 2017. Past due and non-accrual loan amounts exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans.

	March 31, 2018
	Accruing
(Dollars in thousands)	Current or Less Than 30 days Past Due		30-59 days		60-89 days		> 90 days		Total Past Due		Non-accrual		Acquired Impaired		Total
Real estate- construction	$	1,157,115	$	842	$	129	$	—	$	971	$	2,634	$	38,905	$	1,199,625
Real estate- owner-occupied	2,474,611		4,767		3,461		—		8,228		35,144		94,261		2,612,244
Real estate- non-owner-occupied	5,319,962		7,269		2,526		6,789		16,584		9,378		91,158		5,437,082
Commercial and industrial	5,212,390		7,755		3,406		273		11,434		66,637		35,221		5,325,682
Residential mortgage	3,783,309		25,640		2,655		1,226		29,521		19,932		138,305		3,971,067
Consumer - home equity	2,309,222		11,860		3,191		—		15,051		16,383		80,530		2,421,186
Consumer - indirect automobile	48,581		1,166		175		—		1,341		743		6		50,671
Consumer - credit card	92,497		173		88		—		261		503		—		93,261
Consumer - other	585,969		2,484		706		—		3,190		2,621		3,492		595,272
Total	$	20,983,656	$	61,956	$	16,337	$	8,288	$	86,581	$	153,975	$	481,878	$	21,706,090

	December 31, 2017
	Accruing
(Dollars in thousands)	Current or Less Than 30 days Past Due		30-59 days		60-89 days		> 90 days		Total Past Due		Non-accrual		Acquired Impaired		Total
Real estate- construction	$	1,197,766	$	269	$	—	$	458	$	727	$	2,635	$	39,268	$	1,240,396
Real estate- owner-occupied	2,398,487		1,631		659		74		2,364		24,457		104,577		2,529,885
Real estate- non-owner-occupied	5,066,084		2,086		6,405		887		9,378		6,811		85,676		5,167,949
Commercial and industrial	5,014,438		5,788		5,726		146		11,660		77,823		31,146		5,135,067
Residential mortgage	2,877,048		10,083		8,136		5,317		23,536		17,387		138,381		3,056,352
Consumer - home equity	2,186,554		11,675		2,947		18		14,640		12,365		78,716		2,292,275
Consumer - indirect automobile	59,830		1,796		177		—		1,973		884		6		62,693
Consumer - credit card	95,264		140		374		—		514		590		—		96,368
Consumer - other	487,150		3,350		475		—		3,825		2,436		3,785		497,196
Total	$	19,382,621	$	36,818	$	24,899	$	6,900	$	68,617	$	145,388	$	481,555	$	20,078,181

Acquired Loans

As discussed in Note 3, during the third quarter of 2017, the Company acquired loans with fair values of $4.0 billion from Sabadell United. Certain loans that were acquired in this transaction were covered by loss share agreements between the FDIC and Sabadell United, which were assumed in connection with the Company's acquisition of Sabadell United and afford IBERIABANK loss protection. Covered loans were $150.0 million and $158.6 million at March 31, 2018 and December 31, 2017, respectively. Certain acquired loans from Sabadell United were to customers with addresses outside of the United States. Foreign loans, denominated in U.S. dollars, totaled $336.1 million and $325.5 million at March 31, 2018 and December 31, 2017, respectively.

During the first quarter of 2018, the Company acquired loans with fair values of $1.5 billion from Gibraltar.

23

Of the total loans acquired from Gibraltar, $1.46 billion were determined to have no evidence of deteriorated credit quality and are accounted for under ASC Topics 310-10 and 310-20. The remaining $10.2 million were determined to exhibit deteriorated credit quality since origination under ASC 310-30. The tables below show the balances acquired during the first quarter of 2018 for these two subsections of the portfolio as of the acquisition date. These amounts are subject to change due to the finalization of purchase accounting adjustments.

(Dollars in thousands)	Acquired Non-Impaired Loans
Contractually required principal and interest at acquisition	$	1,695,918
Expected losses and foregone interest	(19,952		)
Cash flows expected to be collected at acquisition	1,675,966
Fair value of acquired loans at acquisition	$	1,455,085

(Dollars in thousands)	Acquired Impaired Loans
Contractually required principal and interest at acquisition	$	43,779
Non-accretable difference (expected losses and foregone interest)	(31,174		)
Cash flows expected to be collected at acquisition	12,605
Accretable yield	(2,371		)
Basis in acquired loans at acquisition	$	10,234

The following is a summary of changes in the accretable difference for all loans accounted for under ASC 310-30 during the three months ended March 31:

(Dollars in thousands)	2018			2017
Balance at beginning of period	$	152,623		$	175,054
Additions	2,371			—
Transfers from non-accretable difference to accretable yield	(279		)	2,071
Accretion	(13,154		)	(14,596		)
Changes in expected cash flows not affecting non-accretable differences (1)	9,687			1,060
Balance at end of period	$	151,248		$	163,589

⁽¹⁾  Includes changes in cash flows expected to be collected due to the impact of changes in actual or expected timing of liquidation events, modifications, changes in interest rates and changes in prepayment assumptions.

Troubled Debt Restructurings

Information about the Company’s troubled debt restructurings ("TDRs") at March 31, 2018 and 2017 is presented in the following tables. Modifications of loans that are accounted for within a pool under ASC Topic 310-30 are excluded as TDRs. Accordingly, such modifications do not result in the removal of those loans from the pool, even if the modification of those loans would otherwise be considered a TDR. As a result, all such acquired loans that would otherwise meet the criteria for classification as a TDR are excluded from the tables below.

24

TDRs totaling $27.2 million and $13.2 million occurred during the three months ended March 31, 2018 and March 31, 2017, respectively, through modification of the original loan terms.

The following table provides information on how the TDRs were modified during the periods indicated:

	Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Extended maturities	$	5,619	$	7,199
Maturity and interest rate adjustment	108		3,224
Movement to or extension of interest-rate only payments	48		1,290
Interest rate adjustment	105		—
Forbearance	12,886		1,220
Other concession(s) (1)	8,434		232
Total	$	27,200	$	13,165

⁽¹⁾  Other concessions may include covenant waivers, forgiveness of principal or interest associated with a customer bankruptcy, or a combination of any of the above concessions.

Of the $27.2 million of TDRs occurring during the three months ended March 31, 2018, $12.9 million are on accrual status and $14.3 million are on non-accrual status. Of the $13.2 million of TDRs occurring during the three months ended March 31, 2017, $11.8 million were on accrual status and $1.4 million were on non-accrual status. The following table presents the end of period balance for loans modified in a TDR during the periods indicated:

25

	Three Months Ended March 31,
	2018					2017
(In thousands, except number of loans)	Number of Loans	Pre-modification Outstanding Recorded Investment		Post-modification Outstanding Recorded Investment		Number of Loans	Pre-modification Outstanding Recorded Investment		Post-modification Outstanding Recorded Investment
Real estate- construction	1	$	1,950	$	1,049	—	$	—	$	—
Real estate- owner-occupied	2	10,691		9,324		3	3,004		2,999
Real estate- non-owner-occupied	9	1,089		1,091		7	1,867		1,855
Commercial and industrial	18	14,429		13,314		15	435		427
Residential mortgage	—	—		—		4	259		241
Consumer - home equity	14	1,809		1,795		37	6,622		6,607
Consumer - indirect	11	137		119		13	184		174
Consumer - other	10	511		508		22	867		862
Total	65	$	30,616	$	27,200	101	$	13,238	$	13,165

Information detailing TDRs that defaulted during the three-month periods ended March 31, 2018 and 2017, and were modified in the previous twelve months (i.e., the twelve months prior to the default) is presented in the following tables. The Company has defined a default as any loan with a payment that is currently past due greater than 30 days, or was past due greater than 30 days at any point during the respective periods, or since the date of modification, whichever is shorter.

	Three Months Ended March 31,
	2018			2017
(In thousands, except number of loans)	Number of Loans	Recorded Investment		Number of Loans	Recorded Investment
Real estate- construction	—	$	—	1	$	117
Real estate- owner-occupied	3	10,187		9	14,732
Real estate- non-owner-occupied	9	492		10	5,041
Commercial and industrial	29	9,708		21	4,186
Residential mortgage	6	598		22	1,793
Consumer - home equity	24	2,331		31	1,337
Consumer - indirect automobile	34	322		43	517
Consumer - other	17	1,035		25	693
Total	122	$	24,673	162	$	28,416

26

NOTE 6 – ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY

Allowance for Credit Losses Activity

A summary of changes in the allowance for credit losses for the three months ended March 31 is as follows:

(Dollars in thousands)	2018			2017
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	$	140,891		$	144,719
Provision for loan and lease losses	7,986			6,154
Transfer of balance to OREO and other	(47		)	73
Charge-offs	(9,116		)	(7,291		)
Recoveries	4,813			1,235
Allowance for loan and lease losses at end of period	$	144,527		$	144,890
Reserve for unfunded commitments at beginning of period	$	13,208		$	11,241
Provision for unfunded lending commitments	224			419
Reserve for unfunded commitments at end of period	$	13,432		$	11,660
Allowance for credit losses at end of period	$	157,959		$	156,550

A summary of changes in the allowance for credit losses, by loan portfolio type, for the three months ended March 31 is as follows:

	2018
(Dollars in thousands)	Commercial Real Estate			Commercial and Industrial			Residential Mortgage			Consumer			Total
Allowance for loan and lease losses at beginning of period	$	54,201		$	53,916		$	9,117		$	23,657		$	140,891
Provision for (Reversal of) loan and lease losses	6,377			294			(686		)	2,001			7,986
Transfer of balance to OREO and other	(47		)	—			—			—			(47		)
Charge-offs	(114		)	(5,378		)	(105		)	(3,519		)	(9,116		)
Recoveries	191			3,698			22			902			4,813
Allowance for loan and lease losses at end of period	$	60,608		$	52,530		$	8,348		$	23,041		$	144,527
Reserve for unfunded commitments at beginning of period	$	4,531		$	5,309		$	555		$	2,813		$	13,208
Provision for (Reversal of) unfunded commitments	1,476			(1,004		)	(15		)	(233		)	224
Reserve for unfunded commitments at end of period	$	6,007		$	4,305		$	540		$	2,580		$	13,432
Allowance on loans individually evaluated for impairment	$	2,506		$	14,040		$	178		$	2,974		$	19,698
Allowance on loans collectively evaluated for impairment	35,871			36,208			2,073			16,544			90,696
Allowance on loans acquired with deteriorated credit quality	22,231			2,282			6,097			3,523			34,133
Loans and leases, net of unearned income:
Balance at end of period	$	9,248,951		$	5,325,682		$	3,971,067		$	3,160,390		$	21,706,090
Balance at end of period individually evaluated for impairment	78,489			78,725			6,041			33,277			196,532
Balance at end of period collectively evaluated for impairment	8,946,138			5,211,736			3,826,721			3,043,085			21,027,680
Balance at end of period acquired with deteriorated credit quality	224,324			35,221			138,305			84,028			481,878

27

	2017
(Dollars in thousands)	Commercial Real Estate			Commercial and Industrial			Residential Mortgage			Consumer			Total
Allowance for loan losses at beginning of period	$	49,231		$	60,939		$	11,249		$	23,300		$	144,719
Provision for (Reversal of) loan and lease losses	1,786			2,557			(1,060		)	2,871			6,154
Transfer of balance to OREO and other	377			(350		)	2			44			73
Charge-offs	(95		)	(3,762		)	(22		)	(3,412		)	(7,291		)
Recoveries	196			84			43			912			1,235
Allowance for loan losses at end of period	$	51,495		$	59,468		$	10,212		$	23,715		$	144,890
Reserve for unfunded commitments at beginning of period	$	3,207		$	4,537		$	657		$	2,840		$	11,241
Provision for (Reversal of) unfunded commitments	1,379			(885		)	(49		)	(26		)	419
Reserve for unfunded commitments at end of period	$	4,586		$	3,652		$	608		$	2,814		$	11,660
Allowance on loans individually evaluated for impairment	$	1,916		$	25,056		$	113		$	1,724		$	28,809
Allowance on loans collectively evaluated for impairment	26,872			32,383			3,907			17,764			80,926
Allowance on loans acquired with deteriorated credit quality	22,707			2,029			6,192			4,227			35,155
Loans, net of unearned income:
Balance at end of period	$	7,021,341		$	3,975,734		$	1,296,358		$	2,838,769		$	15,132,202
Balance at end of period individually evaluated for impairment	74,351			164,405			5,048			25,308			269,112
Balance at end of period collectively evaluated for impairment	6,687,651			3,778,775			1,176,017			2,723,308			14,365,751
Balance at end of period acquired with deteriorated credit quality	259,339			32,554			115,293			90,153			497,339

Portfolio Segment Risk Factors

Commercial real estate loans include loans to commercial customers for long-term financing of land and buildings or for land development or construction of a building. These loans are repaid through revenues from operations of the businesses, rents of properties, sales of properties and refinances. Commercial and industrial loans and leases represent loans to commercial customers to finance general working capital needs, equipment purchases and leases and other projects where repayment is derived from cash flows resulting from business operations. The Company originates commercial business loans on a secured and, to a lesser extent, unsecured basis.

Residential mortgage loans consist of loans to consumers to finance a primary residence. The vast majority of the residential mortgage loan portfolio is comprised of non-conforming 1-4 family mortgage loans secured by properties located in the Company's market areas and originated under terms and documentation that permit their sale in a secondary market.

Consumer loans are offered by the Company in order to provide a full range of retail financial services to its customers and include home equity, credit card and other direct consumer installment loans. The Company originates substantially all of its consumer loans in its primary market areas. Loans in the consumer segment are sensitive to unemployment and other key consumer economic measures.

Credit Quality

The Company utilizes an asset risk classification system in accordance with guidelines established by the Federal Reserve Board as part of its efforts to monitor commercial asset quality. “Special mention” loans are defined as loans with potential weaknesses that may, if not corrected, result in future deterioration of the loan. Special mention loans do not expose the Company to sufficient risk to warrant adverse classification. For problem assets with identified credit issues, the Company has two primary classifications: “substandard” and “doubtful.”

28

Substandard assets have one or more defined weaknesses and are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Doubtful assets have the weaknesses of substandard assets with the additional characteristic that the weaknesses make collection or liquidation in full satisfaction of the loan balance outstanding questionable, which makes probability of loss higher based on currently existing facts, conditions, and values. Loans classified as “Pass” do not meet the criteria set forth for special mention, substandard, or doubtful classification and are not considered criticized. Asset risk classifications are determined at origination or acquisition and reviewed on an ongoing basis. Risk classifications are changed if, in the opinion of management, the risk profile of the customer has changed since the last review of the loan relationship.

The Company’s investment in loans by credit quality indicator is presented in the following tables. Asset risk classifications for commercial loans and leases reflect the classification as of March 31, 2018 and December 31, 2017. Credit quality information in the tables below includes total loans acquired (including acquired impaired loans) at the net loan balance, after the application of premiums/discounts, at March 31, 2018 and December 31, 2017. Loan premiums/discounts represent the adjustment of acquired loans to fair value at the acquisition date, as adjusted for income accretion and changes in cash flow estimates in subsequent periods. Loan premiums/discounts include preliminary discounts recorded on acquired Sabadell United and Gibraltar loans, which are subject to change upon receipt of final fair value estimates during the measurement period.

Loan delinquency is the primary credit quality indicator that the Company utilizes to monitor consumer asset quality.

	March 31, 2018										December 31, 2017
(Dollars in thousands)	Pass		Special Mention		Sub- standard		Doubtful		Total		Pass		Special Mention		Sub- standard		Doubtful		Loss		Total
Commercial real estate - construction	$	1,153,604	$	16,399	$	29,610	$	12	$	1,199,625	$	1,189,490	$	20,351	$	30,541	$	14	$	—	$	1,240,396
Commercial real estate - owner-occupied	2,464,072		83,356		56,409		8,407		2,612,244		2,388,715		82,114		56,590		2,466		—		2,529,885
Commercial real estate- non-owner-occupied	5,335,816		45,905		51,089		4,272		5,437,082		5,104,074		19,311		42,702		1,744		118		5,167,949
Commercial and industrial	5,124,676		55,041		107,126		38,839		5,325,682		4,882,554		88,149		128,961		35,403		—		5,135,067
Total	$	14,078,168	$	200,701	$	244,234	$	51,530	$	14,574,633	$	13,564,833	$	209,925	$	258,794	$	39,627	$	118	$	14,073,297

	March 31, 2018						December 31, 2017
(Dollars in thousands)	Current		30+ Days Past Due		Total		Current		30+ Days Past Due		Total
Residential mortgage	$	3,859,751	$	111,316	$	3,971,067	$	2,962,043	$	94,309	$	3,056,352
Consumer - home equity	2,376,171		45,015		2,421,186		2,250,205		42,070		2,292,275
Consumer - indirect automobile	48,587		2,084		50,671		59,836		2,857		62,693
Consumer - credit card	92,497		764		93,261		95,263		1,105		96,368
Consumer - other	589,098		6,174		595,272		490,399		6,797		497,196
Total	$	6,966,104	$	165,353	$	7,131,457	$	5,857,746	$	147,138	$	6,004,884

29

Impaired Loans

Information on the Company’s investment in impaired loans, which include all TDRs and all other non-accrual loans evaluated or measured individually for impairment for purposes of determining the ALLL, is presented in the following tables as of and for the periods indicated.

	March 31, 2018							December 31, 2017
	Unpaid Principal Balance		Recorded Investment		Related Allowance			Unpaid Principal Balance		Recorded Investment		Related Allowance
(Dollars in thousands)
With no related allowance recorded:
Commercial real estate- construction	$	11,153	$	11,153	$	—		$	13,763	$	13,013	$	—
Commercial real estate- owner-occupied	43,562		36,042		—			50,867		44,482		—
Commercial real estate- non-owner-occupied	10,575		10,449		—			15,370		14,975		—
Commercial and industrial	45,720		36,829		—			103,013		70,254		—
Residential mortgage	1,083		1,083		—			2,004		2,001		—
Consumer - home equity	31		31		—			5,906		5,634		—
Consumer -other	—		—		—			75		75		—
With an allowance recorded:
Commercial real estate- construction	236		154		(18		)	238		156		(19		)
Commercial real estate- owner-occupied	17,536		17,419		(1,860		)	13,314		13,287		(949		)
Commercial real estate- non-owner-occupied	3,399		3,272		(628		)	6,051		5,872		(620		)
Commercial and industrial	46,705		41,896		(14,040		)	35,306		32,162		(12,736		)
Residential mortgage	5,357		4,958		(178		)	5,179		4,748		(172		)
Consumer - home equity	28,917		28,187		(2,435		)	27,189		26,575		(2,358		)
Consumer - indirect automobile	1,004		656		(75		)	1,034		679		(79		)
Consumer - other	4,493		4,403		(464		)	4,320		4,214		(419		)
Total	$	219,771	$	196,532	$	(19,698	)	$	283,629	$	238,127	$	(17,352	)
Total commercial loans and leases	$	178,886	$	157,214	$	(16,546	)	$	237,922	$	194,201	$	(14,324	)
Total mortgage loans	6,440		6,041		(178		)	7,183		6,749		(172		)
Total consumer loans	34,445		33,277		(2,974		)	38,524		37,177		(2,856		)

30

	Three Months Ended March 31, 2018				Three Months Ended March 31, 2017
	Average Recorded Investment		Interest Income Recognized		Average Recorded Investment		Interest Income Recognized
(Dollars in thousands)
With no related allowance recorded:
Commercial real estate- construction	$	10,470	$	144	$	—	$	—
Commercial real estate- owner-occupied	36,277		334		37,197		339
Commercial real estate- non-owner-occupied	10,557		98		5,988		17
Commercial and industrial	27,832		385		90,664		448
Residential mortgage	1,090		12		735		5
Consumer - home equity	32		—		4,158		40
With an allowance recorded:
Commercial real estate- construction	153		1		1,984		1
Commercial real estate- owner-occupied	17,608		112		20,980		79
Commercial real estate- non-owner-occupied	3,302		10		8,587		94
Commercial and industrial	44,056		196		78,695		220
Residential mortgage	4,974		44		4,335		42
Consumer - home equity	28,203		292		16,713		179
Consumer - indirect automobile	717		5		767		7
Consumer - other	4,483		62		3,328		52
Total	$	189,754	$	1,695	$	274,131	$	1,523
Total commercial loans and leases	$	150,255	$	1,280	$	244,095	$	1,198
Total mortgage loans	6,064		56		5,070		47
Total consumer loans	33,435		359		24,966		278

As of March 31, 2018 and December 31, 2017, the Company was not committed to lend a material amount of additional funds to any customer whose loan was classified as impaired or as a troubled debt restructuring.

31

NOTE 7 – GOODWILL AND OTHER INTANGIBLE ASSETS

Goodwill

Changes to the carrying amount of goodwill by reporting unit for the three months ended March 31, 2018, and the year ended December 31, 2017 are provided in the following table.

(Dollars in thousands)	IBERIABANK		Mortgage		LTC		Total
Balance, December 31, 2016	$	698,513	$	23,178	$	5,165	$	726,856
Goodwill acquired during the year (preliminary allocation)	462,046		—		—		462,046
Balance, December 31, 2017	$	1,160,559	$	23,178	$	5,165	$	1,188,902
Goodwill acquired during the year (preliminary allocation) and adjustments	43,887		—		3,380		47,267
Balance, March 31, 2018	$	1,204,446	$	23,178	$	8,545	$	1,236,169

On March 23, 2018 the Company completed its acquisition of Gibraltar. In connection with the acquisition, the Company recorded $42.5 million of goodwill based on preliminary adjustments. On January 12, 2018, the Company's subsidiary, LTC, completed its acquisition of SolomonParks. In connection with the acquisition, LTC recorded $3.4 million of goodwill based on preliminary adjustments. In addition, goodwill adjustments were made during the first three months of 2018 as a result of measurement period updates to the preliminary fair value estimates related to the 2017 acquisition of Sabadell United. See Note 3 for additional information regarding these acquisitions.

The Company performed the required annual goodwill impairment test as of October 1, 2017. The Company’s annual impairment test did not indicate impairment in any of the Company’s reporting units as of the testing date. Following the testing date, management evaluated the events and changes that could indicate that goodwill might be impaired and concluded that a subsequent interim test was not necessary.

Mortgage Servicing Rights

Mortgage servicing rights are recorded at the lower of cost or market value in “other intangible assets” on the Company's consolidated balance sheets and amortized over the remaining servicing life of the loans, with consideration given to prepayment assumptions. Mortgage servicing rights had the following carrying values as of the periods indicated:

	March 31, 2018							December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
(Dollars in thousands)
Mortgage servicing rights	$	10,030	$	(4,128	)	$	5,902	$	9,588	$	(3,931	)	$	5,657

In addition, there was an insignificant amount of non-mortgage servicing rights related to SBA loans as of March 31, 2018 and December 31, 2017, respectively.

Title Plant

The Company held title plant assets recorded in “other intangible assets” on the Company's consolidated balance sheets totaling $6.8 million on March 31, 2018 and $6.7 million on December 31, 2017. The increase in title plant assets was the result of the SolomonParks acquisition during the first quarter of 2018. No events or changes in circumstances occurred during the three months ended March 31, 2018 to suggest the carrying value of the title plant was not recoverable.

32

Intangible assets subject to amortization

In connection with the acquisition of Gibraltar, the Company recorded $18.5 million of core deposit intangible assets. Core deposit intangible assets are subject to amortization over a ten year period. In connection with the acquisition of SolomonParks, the Company recorded $155.9 thousand of non-compete agreement intangible assets. Non-compete agreement intangible assets are subject to amortization over a five year period. Definite-lived intangible assets had the following carrying values included in “other intangible assets” on the Company’s consolidated balance sheets as of the periods indicated:

	March 31, 2018							December 31, 2017
(Dollars in thousands)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Core deposit intangible assets	$	136,183	$	(46,736	)	$	89,447	$	127,957	$	(51,971	)	$	75,986
Customer relationship intangible asset	1,385		(1,262		)	123		1,143		(996		)	147
Non-compete agreement	206		(36		)	170		63		(39		)	24
Total	$	137,774	$	(48,034	)	$	89,740	$	129,163	$	(53,006	)	$	76,157

33

NOTE 8 – DERIVATIVE INSTRUMENTS AND OTHER HEDGING ACTIVITIES

The Company enters into derivative financial instruments to manage interest rate risk, exposures related to liquidity and credit risk, and to facilitate customer transactions. The primary types of derivatives used by the Company include interest rate swap agreements, foreign exchange contracts, interest rate lock commitments, forward sales commitments, written and purchased options and credit derivatives. All derivative instruments are recognized on the consolidated balance sheets as "other assets" or "other liabilities" at fair value, as required by ASC Topic 815, Derivatives and Hedging.

For cash flow hedges, the effective and ineffective portions of the gain or loss related to the derivative instrument is initially reported as a component of other comprehensive income and subsequently reclassified into earnings when the forecasted transaction affects earnings or when the hedge is terminated, per the Company’s early adoption of ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities, as of January 1, 2018. In applying hedge accounting for derivatives, the Company establishes and documents a method for assessing the effectiveness of the hedging derivative and a measurement approach for determining the ineffective aspect of the hedge upon the inception of the hedge. The Company has designated interest rate swaps in a cash flow hedge to convert forecasted variable interest payments to a fixed rate on its junior subordinated debt and has concluded that the forecasted transactions are probable of occurring.

For derivative instruments that are not designated as hedging instruments, changes in the fair value of the derivatives are recognized in earnings immediately.

Information pertaining to outstanding derivative instruments is as follows:

	Balance Sheet Location	Derivative Assets - Fair Value				Balance Sheet Location	Derivative Liabilities - Fair Value
(Dollars in thousands)		March 31, 2018		December 31, 2017			March 31, 2018		December 31, 2017
Derivatives designated as hedging instruments under ASC Topic 815:
Interest rate contracts	Other assets	$	—	$	—	Other liabilities	$	—	$	—
Total derivatives designated as hedging instruments under ASC Topic 815		$	—	$	—		$	—	$	—
Derivatives not designated as hedging instruments under ASC Topic 815:
Interest rate contracts	Other assets	$	5,827	$	20,446	Other liabilities	$	25,771	$	16,191
Foreign exchange contracts	Other assets	2		7		Other liabilities	2		7
Forward sales contracts	Other assets	2,851		136		Other liabilities	703		279
Written and purchased options	Other assets	8,383		10,654		Other liabilities	5,667		8,656
Other contracts	Other assets	9		22		Other liabilities	11		21
Total derivatives not designated as hedging instruments under ASC Topic 815		$	17,072	$	31,265		$	32,154	$	25,154
Total		$	17,072	$	31,265		$	32,154	$	25,154

34

	Derivative Assets - Notional Amount				Derivative Liabilities - Notional Amount
(Dollars in thousands)	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
Derivatives designated as hedging instruments under ASC Topic 815:
Interest rate contracts	$	108,500	$	—	$	—	$	108,500
Total derivatives designated as hedging instruments under ASC Topic 815	$	108,500	$	—	$	—	$	108,500
Derivatives not designated as hedging instruments under ASC Topic 815:
Interest rate contracts	$	1,356,990	$	1,218,464	$	1,276,990	$	1,218,464
Foreign exchange contracts	628		268		628		268
Forward sales contracts	96,810		82,347		215,918		142,578
Written and purchased options	339,852		278,638		164,341		165,198
Other contracts	29,676		29,755		71,889		86,744
Total derivatives not designated as hedging instruments under ASC Topic 815	$	1,823,956	$	1,609,472	$	1,729,766	$	1,613,252
Total	$	1,932,456	$	1,609,472	$	1,729,766	$	1,721,752

The Company has entered into risk participation agreements with counterparties to transfer or assume credit exposures related to interest rate derivatives. The notional amounts of risk participation agreements sold were $71.9 million and $86.7 million at March 31, 2018 and December 31, 2017, respectively. Assuming all underlying third party customers referenced in the swap contracts defaulted at March 31, 2018 and December 31, 2017, the exposure from these agreements would not be material based on the fair value of the underlying swaps.

The Company is party to collateral agreements with certain derivative counterparties. Such agreements require that the Company maintain collateral based on the fair values of individual derivative transactions. In the event of default by the Company, the counterparty would be entitled to the collateral.

At March 31, 2018, the Company was not required to post collateral due to the Company's derivative position at the balance sheet date. At December 31, 2017, the Company was required to post $552 thousand in cash or securities as collateral for its derivative transactions, which is included in "interest-bearing deposits in banks" on the Company’s consolidated balance sheets. Effective January 3, 2017, the Chicago Mercantile Exchange and LCH.Clearnet Limited amended their rulebooks to legally characterize variation margin payments for over-the-counter derivatives they clear as settlements of the derivatives' exposure rather than collateral against the exposures. In light of changes to the aforementioned rulebooks, the Board of Governors of the Federal Reserve System, the Office of the Comptroller of the Currency (OCC) and the FDIC issued guidance effective August 14, 2017, which is consistent with the SEC's accounting guidance, that allows institutions to treat centrally-cleared derivatives as settled for purposes of the capital rule. At March 31, 2018 and December 31, 2017, the Company was required to post $28.8 million and $5.1 million, respectively, in variation margin payments for its derivative transactions, which is now required to be netted against the fair value of the derivatives in "other assets/other liabilities" on the consolidated balance sheets. The Company does not anticipate additional assets will be required to be posted as collateral, nor does it believe additional assets would be required to settle its derivative instruments immediately if contingent features were triggered at March 31, 2018. The Company’s master netting agreements represent written, legally enforceable bilateral agreements that (1) create a single legal obligation for all individual transactions covered by the master agreement and (2) in the event of default, provide the non-defaulting counterparty the right to accelerate, terminate, and close-out on a net basis all transactions under the agreement and to promptly liquidate or set-off collateral posted by the defaulting counterparty. As permitted by U.S. GAAP, the Company does not offset fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral against recognized fair value amounts of derivatives executed with the same counterparty under a master netting agreement.

35

The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset.

	March 31, 2018
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet					Net
(Dollars in thousands)			Derivatives			Collateral  (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	5,827	$	(548	)	$	—	$	5,279
Written and purchased options	5,656		—			—		5,656
Total derivative assets subject to master netting arrangements	$	11,483	$	(548	)	$	—	$	10,935
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—	$	—
Interest rate contracts not designated as hedging instruments	25,771		(548		)	—		25,223
Written and purchased options	5,587		—			—		5,587
Total derivative liabilities subject to master netting arrangements	$	31,358	$	(548	)	$	—	$	30,810

^{(1) Consists of cash collateral recorded at cost, which approximates fair value, and investment securities.} 

	December 31, 2017
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet						Net
(Dollars in thousands)			Derivatives			Collateral (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	20,446	$	(12,469	)	$	—		$	7,977
Written and purchased options	8,610		—			—			8,610
Total derivative assets subject to master netting arrangements	$	29,056	$	(12,469	)	$	—		$	16,587
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—		$	—
Interest rate contracts not designated as hedging instruments	16,191		(12,469		)	(552		)	3,170
Total derivative liabilities subject to master netting arrangements	$	16,191	$	(12,469	)	$	(552	)	$	3,170

^{(1) Consists of cash collateral recorded at cost, which approximates fair value, and investment securities.} 

During the three months ended March 31, 2018 and 2017, the Company has not reclassified into earnings any gain or loss as a result of the discontinuance of cash flow hedges, because it was probable the original forecasted transaction would not occur by the end of the originally specified term.

At March 31, 2018, the Company does not expect to reclassify a material amount from accumulated other comprehensive income into interest income over the next twelve months for derivatives that will be settled.

36

At March 31, 2018 and 2017, and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements is as follows:

													Location of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	Amount of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)
			Amount of Gain (Loss) Recognized in OCI, net of taxes			Location of Gain (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain (Loss) Reclassified from Accumulated OCI into Income, net of taxes
(Dollars in thousands)
			For the Three Months Ended March 31
Derivatives in ASC Topic 815 Cash Flow Hedging Relationships		2018		2017			2018			2017				2018		2017
	Interest rate contracts	$	2,549	$	73	Interest expense	$	(116	)	$	(45	)	Interest expense	$	—	$	—
Total		$	2,549	$	73		$	(116	)	$	(45	)		$	—	$	—

Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, is as follows:

	Location of Gain (Loss) Recognized in  Income on Derivatives	Amount of Gain (Loss) Recognized in Income on Derivatives
		For the Three Months Ended March 31
(Dollars in thousands)		2018			2017
Interest rate contracts (1)	Other income	$	1,049		$	1,117
Foreign exchange contracts	Other income	5			7
Forward sales contracts	Mortgage income	3,387			(360		)
Written and purchased options	Mortgage income	648			655
Other contracts	Other income	(3		)	4
Total		$	5,086		$	1,423

^{(1) Includes fees associated with customer interest rate contracts.} 

37

NOTE 9 – INCOME TAXES

The Company's provision for income taxes for the three months ended March 31, 2018 and 2017 is based on the estimated annual effective tax rate, plus discrete items.

The following table presents the provision for income taxes and the effective tax rates for the three months ended March 31, 2018 and 2017:

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Income before income tax expense	$	81,173		$	72,992
Income tax expense	17,552			22,519
Effective tax rate	21.6		%	30.9		%

The difference between the Company's effective tax rates for the three months ended March 31, 2018 and 2017 and the U.S. statutory tax rates of 21% and 35%, respectively, primarily relates to tax-exempt income, non-deductible expenses, state income taxes (net of federal income tax benefit), and the recognition of tax credits. The effective tax rate may vary significantly due to fluctuations in the amount and source of pretax income, changes in amounts of non-deductible expenses, and timing of the recognition of tax credits.

Provisional amounts in effective tax rate

On December 22, 2017, President Trump signed the Tax Cuts and Jobs Act (the "Tax Act") into law. Under ASC 740, the effects of changes in tax rates and laws are recognized in the period in which the new legislation is enacted. In the case of U.S. federal income taxes, the enactment date is the date the bill becomes law (i.e., upon presidential signature). Among other provisions, the most significant to the Company is the reduction of the corporate income tax rate from 35% to 21%. With respect to the legislation, the Company recognized a provisional one-time increase in tax expense of $51.0 million as of December 31, 2017 due to a re-measurement of deferred tax assets and liabilities resulting from the decrease in the corporate income tax rate. During the three months ended March 31, 2018, the Company made no adjustment to the provisional amounts recorded at December 31, 2017, and the accounting for the tax effects of the Tax Act remain incomplete as of March 31, 2018. The Company is in the process of analyzing certain aspects of the Tax Act, obtaining additional information, and refining its calculations, which could potentially affect the measurement of these balances. Information which could result in adjustment to the provisional amount includes, but is not limited to, provisional deferred tax amounts acquired in the Sabadell United acquisition, elections or changes in IRS tax methods, and further analysis of tax positions. Our estimates may also be affected as we gain a more thorough understanding of the Tax Act. Consistent with the guidance provided under ASC 740, the Company recorded impacts from enactment of the Tax Act in the fourth quarter of 2017 subject to Staff Accounting Bulletin 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act ("SAB 118"). SAB 118 provides a measurement period not to extend beyond one year of the enactment date to adjust the accounting for certain elements of the tax reform.

38

NOTE 10 – SHAREHOLDERS' EQUITY, CAPITAL RATIOS AND OTHER REGULATORY MATTERS

Preferred Stock

The following table presents a summary of the Company's non-cumulative perpetual preferred stock:

							March 31, 2018		December 31, 2017
	Issuance Date	Earliest Redemption Date	Annual Dividend Rate		Liquidation Amount		Carrying Amount		Carrying Amount
(Dollars in thousands)
Series B Preferred Stock	8/5/2015	8/1/2025	6.625	%	$	80,000	$	76,812	$	76,812
Series C Preferred Stock	5/9/2016	5/1/2026	6.600	%	57,500		55,285		55,285
					$	137,500	$	132,097	$	132,097

Common Stock

During the second quarter of 2016, the Company's Board of Directors authorized the repurchase of up to 950,000 shares of IBERIABANK Corporation's outstanding common stock. Stock repurchases under this program will be made from time to time, on the open market or in privately negotiated transactions. The timing of these repurchases will depend on market conditions and other requirements. The share repurchase program does not obligate the Company to repurchase any dollar amount or number of shares, and expires during the second quarter of 2018. The program may be extended, modified, suspended, or discontinued at any time. The Company did not repurchase any shares during the quarter ended March 31, 2018. At March 31, 2018, the remaining common shares that could be repurchased under the plan approved by the Board was 747,494 shares. Subsequent to quarter-end and through May 7, 2018, the Company repurchased 300,000 common shares for approximately $22.7 million.

On March 23, 2018, as part of the Gibraltar acquisition, the Company issued 2,787,773 shares of common stock. The aggregate value of the acquisition consideration paid by the Company at the time of closing was approximately $214.7 million based on the Company's closing common stock price of $77.00 per share on March 23, 2018. Gibraltar common shareholders received 1.9749 shares of IBERIABANK Corporation common stock for each outstanding share of Gibraltar common stock. Refer to Note 3, Acquisition Activity, for further detail regarding the Gibraltar acquisition.

Regulatory Capital

The Company and IBERIABANK are subject to various regulatory capital requirements administered by the federal and state banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy regulations and the regulatory framework for prompt corrective action, the Company and IBERIABANK, as applicable, must meet specific capital guidelines that involve quantitative measures of their assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors.

Management believes that, as of March 31, 2018, the Company and IBERIABANK met all capital adequacy requirements to which they are subject.

As of March 31, 2018, the most recent notification from the FRB categorized IBERIABANK as well-capitalized under the regulatory framework for prompt corrective action (the prompt corrective action requirements are not applicable to the Company). To be categorized as well-capitalized, an institution must maintain minimum total risk-based, Tier 1 risk-based and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since the notification that management believes have changed that categorization.

39

The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2018 and December 31, 2017 are presented in the following tables.

(Dollars in thousands)	March 31, 2018
	Minimum				Well-Capitalized		Actual
	Amount		Ratio		Amount	Ratio	Amount		Ratio
Tier 1 Leverage
Consolidated	$	1,076,933	4.00	%	N/A	N/A	$	2,685,315	9.97	%
IBERIABANK	1,074,579		4.00		1,343,223	5.00	2,640,916		9.83
Common Equity Tier 1 (CET1) (1)
Consolidated	$	1,067,284	4.50	%	N/A	N/A	$	2,553,218	10.77	%
IBERIABANK	1,065,059		4.50		1,538,418	6.50	2,640,916		11.16
Tier 1 Risk-Based Capital (1)
Consolidated	$	1,423,046	6.00	%	N/A	N/A	$	2,685,315	11.32	%
IBERIABANK	1,420,078		6.00		1,893,437	8.00	2,640,916		11.16
Total Risk-Based Capital (1)
Consolidated	$	1,897,394	8.00	%	N/A	N/A	$	2,959,774	12.48	%
IBERIABANK	1,893,437		8.00		2,366,797	10.00	2,798,875		11.83

	December 31, 2017
	Minimum				Well-Capitalized		Actual
	Amount		Ratio		Amount	Ratio	Amount		Ratio
Tier 1 Leverage
Consolidated	$	1,073,381	4.00	%	N/A	N/A	$	2,509,496	9.35	%
IBERIABANK	1,070,789		4.00		1,338,487	5.00	2,437,275		9.10
Common Equity Tier 1 (CET1) (1)
Consolidated	$	1,011,732	4.50	%	N/A	N/A	$	2,377,398	10.57	%
IBERIABANK	1,009,553		4.50		1,458,243	6.50	2,437,275		10.86
Tier 1 Risk-Based Capital (1)
Consolidated	$	1,348,977	6.00	%	N/A	N/A	$	2,509,496	11.16	%
IBERIABANK	1,346,070		6.00		1,794,760	8.00	2,437,275		10.86
Total Risk-Based Capital (1)
Consolidated	$	1,798,635	8.00	%	N/A	N/A	$	2,780,095	12.37	%
IBERIABANK	1,794,760		8.00		2,243,450	10.00	2,591,374		11.55

⁽¹⁾ Minimum capital ratios are subject to a capital conservation buffer. In order to avoid limitations on distributions, including dividend payments, and certain discretionary bonus payments to executive officers, an institution must hold a capital conservation buffer above its minimum risk-based capital requirements. This capital conservation buffer is calculated as the lowest of the differences between the actual CET1 ratio, Tier 1 Risk-Based Capital Ratio, and Total Risk-Based Capital ratio and the corresponding minimum ratios. At March 31, 2018, the required minimum capital conservation buffer was 1.875%, and will increase by 0.625% and be fully phased-in on January 1, 2019 at 2.50%. At March 31, 2018, the capital conservation buffers of the Company and IBERIABANK were 4.48% and 3.83%, respectively.

40

NOTE 11 – EARNINGS PER SHARE

Share-based payment awards that entitle holders to receive non-forfeitable dividends before vesting are considered participating securities that are included in the calculation of earnings per share using the two-class method. The two-class method is an earnings allocation formula under which earnings per share is calculated for common stock and participating securities according to dividends declared and participating rights in undistributed earnings. Under this method, all earnings, distributed and undistributed, are allocated to common shares and participating securities based on their respective rights to receive dividends.

The following table presents the calculation of basic and diluted earnings per share for the periods indicated.

	Three Months Ended March 31,
(In thousands, except per share data)	2018			2017
Earnings per common share - basic:
Net income	$	63,621		$	50,473
Less: Preferred stock dividends	3,598			3,599
Less: Dividends and undistributed earnings allocated to unvested restricted shares	639			346
Net income allocated to common shareholders - basic	$	59,384		$	46,528
Weighted average common shares outstanding	53,616			46,123
Earnings per common share - basic	1.11			1.01
Earnings per common share - diluted:
Net income allocated to common shareholders - basic	$	59,384		$	46,528
Adjustment for undistributed earnings allocated to unvested restricted shares	(18		)	(37		)
Net income allocated to common shareholders - diluted	$	59,366		$	46,491
Weighted average common shares outstanding	53,616			46,123
Dilutive potential common shares	351			373
Weighted average common shares outstanding - diluted	53,967			46,496
Earnings per common share - diluted	$	1.10		$	1.00

For the three months ended March 31, 2018, and 2017, the calculations for basic shares outstanding exclude the weighted average shares owned by the Recognition and Retention Plan (“RRP”) of 606,442 and 406,896, respectively.

The effects from the assumed exercises of 156,737 and 70,456 stock options were not included in the computation of diluted earnings per share for the three months ended March 31, 2018 and 2017, respectively, because such amounts would have had an antidilutive effect on earnings per common share.

41

NOTE 12 – SHARE-BASED COMPENSATION

The Company has various types of share-based compensation plans that permit the granting of awards in the form of stock options, restricted stock, restricted share units and phantom stock. These plans are administered by the Compensation Committee of the Board of Directors, which selects persons eligible to receive awards and determines the terms, conditions and other provisions of the awards. At March 31, 2018, awards of 1,166,797 shares could be made under approved incentive compensation plans. The Company issues shares to fulfill stock option exercises and restricted share units and restricted stock awards vesting from available authorized common shares. At March 31, 2018, the Company believes there are adequate authorized shares to satisfy anticipated stock option exercises and restricted share unit and restricted stock award vesting.

Stock option awards

The Company issues stock options under various plans to directors, officers and other key employees. The option exercise price cannot be less than the fair value of the underlying common stock as of the date of the option grant and the maximum option term cannot exceed ten years.

The following table represents the activity related to stock options during the periods indicated:

	Number of Shares		Weighted Average Exercise Price
Outstanding options, December 31, 2016	721,538		$	55.38
Granted	70,433		85.52
Exercised	(24,457	)	53.85
Forfeited or expired	(12,539	)	75.77
Outstanding options, March 31, 2017	754,975		$	57.90
Exercisable options, March 31, 2017	509,347		$	55.78
Outstanding options, December 31, 2017	686,366		$	58.24
Granted	92,162		82.20
Exercised	(21,212	)	52.10
Forfeited or expired	(14,513	)	65.27
Outstanding options, March 31, 2018	742,803		$	61.25
Exercisable options, March 31, 2018	519,496		$	56.53

The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. The following weighted-average assumptions were used for option awards issued during the following periods:

	For the Three Months Ended March 31,
	2018			2017
Expected dividends	1.8		%	1.7		%
Expected volatility	24.3		%	24.9		%
Risk-free interest rate	2.7		%	2.1		%
Expected term (in years)	5.7			5.6
Weighted-average grant-date fair value	$	18.36		$	18.75

The assumptions above are based on multiple factors, including historical stock option exercise patterns and post-vesting employment termination behaviors, expected future exercise patterns and the expected volatility of the Company’s stock price.

42

The following table represents the compensation expense that is included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to stock options for the following periods:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to stock options	$	312	$	444
Income tax benefit related to stock options	23		68

At March 31, 2018, there was $2.8 million of unrecognized compensation expense related to stock options that is expected to be recognized over a weighted-average period of 3.2 years.

Restricted stock awards

The Company issues restricted stock under various plans for certain officers and directors. The restricted stock awards may not be sold or otherwise transferred until certain restrictions have lapsed. The holders of the restricted stock receive dividends and have the right to vote the shares. The compensation expense for these awards is determined based on the market price of the Company's common stock at the date of grant applied to the total number of shares granted and is recognized over the vesting period (generally three to five years). As of March 31, 2018 and 2017, unrecognized share-based compensation expense associated with these awards totaled $39.0 million and $21.4 million, respectively. The unrecognized compensation expense related to restricted stock awards at March 31, 2018 is expected to be recognized over a weighted-average period of 1.5 years.

Restricted share units

During the first three months of 2018 and 2017, the Company issued restricted share units to certain of its executive officers. Restricted share units vest after the end of a three year performance period, based on satisfaction of the market and performance conditions set forth in the restricted share unit agreements. Recipients do not possess voting or investment power over the common stock underlying such units until vesting. The grant date fair value of these restricted share units is the same as the value of the corresponding number of shares of common stock, adjusted for assumptions surrounding the market-based conditions contained in the respective agreements. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017, for further discussion of restricted share units with market or performance conditions.

The following table represents the compensation expense that was included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to restricted stock awards and restricted share units for the periods indicated:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to restricted stock awards and restricted share units	$	4,422	$	3,277
Income tax benefit related to restricted stock awards and restricted share units	929		1,147

The following table represents unvested restricted stock award and restricted share unit activity for the following periods:

	For the Three Months Ended March 31,
	2018		2017
Number of shares at beginning of period	738,187		543,258
Granted	199,958		146,175
Forfeited	(43,405	)	(4,105	)
Vested	(115,877	)	(157,753	)
Number of shares at end of period	778,863		527,575

43

Phantom stock awards

The Company issues phantom stock awards to certain key officers and employees. The awards are subject to a vesting period of five years and are paid out in cash upon vesting. The amount paid per vesting period is calculated as the number of vested “share equivalents” multiplied by the closing market price of a share of the Company’s common stock on the vesting date. Share equivalents are calculated on the date of grant as the total award’s dollar value divided by the closing market price of a share of the Company’s common stock on the grant date. Award recipients are also entitled to a “dividend equivalent” on each unvested share equivalent held by the award recipient. A dividend equivalent is a dollar amount equal to the cash dividends that the participant would have been entitled to receive if the participant’s share equivalents were issued in shares of common stock. Dividend equivalents are reinvested as share equivalents that will vest and be paid out on the same date as the underlying share equivalents on which the dividend equivalents were paid. The number of share equivalents accumulated with a dividend equivalent is determined by dividing the aggregate of dividend equivalents paid on the unvested share equivalents by the closing price of a share of the Company’s common stock on the dividend payment date.

The following table indicates compensation expense recorded for phantom stock based on the number of share equivalents vested at March 31 of the periods indicated and the current market price of the Company’s stock at that time:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to phantom stock	$	2,996	$	3,053

The following table represents phantom stock award activity during the periods indicated.

(Dollars in thousands)	Number of share equivalents (1)		Value of share equivalents (2)
Balance, December 31, 2016	472,830		$	39,600
Granted	96,897		7,665
Forfeited share equivalents	(5,330	)	422
Vested share equivalents	(143,643	)	12,024
Balance, March 31, 2017	420,754		$	33,282
Balance, December 31, 2017	393,844		$	30,523
Granted	129,234		10,080
Forfeited share equivalents	(24,460	)	1,908
Vested share equivalents	(121,758	)	10,187
Balance, March 31, 2018	376,860		$	29,395

⁽¹⁾  Number of share equivalents includes all reinvested dividend equivalents for the periods indicated.

⁽²⁾  Except for share equivalents at the beginning of each period, which are based on the value at that time, and vested share payments, which are based on the cash paid at the time of vesting, the value of share equivalents is calculated based on the market price of the Company’s stock at the end of the respective periods. The market price of the Company’s stock was $78.00 and $79.10 on March 31, 2018, and 2017, respectively.

44

NOTE 13 – FAIR VALUE MEASUREMENTS

Recurring fair value measurements

The Company has segregated all financial assets and liabilities that are measured at fair value on a recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to estimate the fair value at the measurement date in the tables below. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017, for a description of how fair value measurements are determined.

	March 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Securities available for sale	$	—	$	4,542,486	$	—	$	4,542,486
CRA and Community Development Investment Funds	—		9,801		—		9,801
Mortgage loans held for sale	—		110,348		—		110,348
Derivative instruments	—		17,072		—		17,072
Total	$	—	$	4,679,707	$	—	$	4,679,707
Liabilities
Derivative instruments	$	—	$	32,154	$	—	$	32,154
Total	$	—	$	32,154	$	—	$	32,154
	December 31, 2017
	Level 1		Level 2		Level 3		Total
Assets
Securities available for sale	$	—	$	4,590,062	$	—	$	4,590,062
Mortgage loans held for sale	—		134,916		—		134,916
Derivative instruments	—		31,265		—		31,265
Total	$	—	$	4,756,243	$	—	$	4,756,243
Liabilities
Derivative instruments	$	—	$	25,154	$	—	$	25,154
Total	$	—	$	25,154	$	—	$	25,154

During the three months ended March 31, 2018, there were no transfers between the Level 1 and Level 2 fair value categories.

Non-recurring fair value measurements

The Company has segregated all assets and liabilities that are measured at fair value on a non-recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date in the tables below.

	March 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Loans	$	—	$	—	$	85,269	$	85,269
OREO, net	—		—		2,234		2,234
Total	$	—	$	—	$	87,503	$	87,503
	December 31, 2017
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Loans	$	—	$	—	$	71,210	$	71,210
OREO, net	—		—		3,029		3,029
Total	$	—	$	—	$	74,239	$	74,239

45

The tables above exclude the initial measurement of assets and liabilities that were acquired as part of the Sabadell United acquisition in July of 2017 and the Gibraltar acquisition in March of 2018. These assets and liabilities were recorded at their fair value upon acquisition in accordance with U.S. GAAP and were not re-measured during the periods presented unless specifically required by U.S. GAAP. Acquisition date fair values represent either Level 2 fair value measurements (investment securities, deposits, property, equipment, and debt) or Level 3 fair value measurements (loans and core deposit intangible assets.) Refer to Note 3, Acquisition Activity, for further detail regarding the Sabadell United and Gibraltar acquisitions.

In accordance with the provisions of ASC Topic 310, the Company records certain loans considered impaired at their estimated fair value. A loan is considered impaired if it is probable the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Fair value is measured at the estimated fair value of the collateral for collateral-dependent loans.

The Company did not record any liabilities at fair value for which measurement of the fair value was made on a non-recurring basis as of March 31, 2018 and December 31, 2017.

Fair value option

The Company has elected the fair value option for certain originated residential mortgage loans held for sale, which allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to hedge them without the burden of complying with the requirements for hedge accounting. The Company has $17.0 million and $15.0 million of mortgage loans held for investment for which the fair value option was elected upon origination and continue to be accounted for at fair value at March 31, 2018 and December 31, 2017, respectively. Net gains (losses) resulting from the change in fair value of these loans that were recorded in mortgage income in the consolidated statements of comprehensive income for the three months ended March 31, 2018 and 2017 totaled $(749) thousand and $(409) thousand, respectively.

The following table summarizes the difference between the aggregate fair value and the aggregate unpaid principal balance for mortgage loans held for sale measured at fair value:

	March 31, 2018						December 31, 2017
(Dollars in thousands)	Aggregate Fair Value		Aggregate Unpaid Principal		Aggregate Fair Value Less Unpaid Principal		Aggregate Fair Value		Aggregate Unpaid Principal		Aggregate Fair Value Less Unpaid Principal
Mortgage loans held for sale, at fair value	$	110,348	$	107,849	$	2,499	$	134,916	$	131,276	$	3,640

Interest income on mortgage loans held for sale is recognized based on contractual rates and is reflected in interest income on loans held for sale in the consolidated statements of comprehensive income. Net gains (losses) resulting from the change in fair value of these loans that were recorded in mortgage income in the consolidated statements of comprehensive income for the three months ended March 31, 2018 and 2017 totaled $(1.1) million and $839 thousand, respectively. The changes in fair value are mostly offset by economic hedging activities, with an insignificant portion of these changes attributable to changes in instrument-specific credit risk.

46

NOTE 14 – FAIR VALUE OF FINANCIAL INSTRUMENTS

The estimated fair value of a financial instrument is the current amount that would be exchanged between willing parties, other than in a forced liquidation. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. ASC Topic 825, Financial Instruments, excludes certain financial instruments and all non-financial instruments from its disclosure requirements. Consequently, the aggregate fair value amounts presented may not necessarily represent the underlying fair value of the Company.

The carrying amount and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are included in the tables below. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017 for a description of how fair value measurements are determined, except for loans, amended upon implementation of ASU 2016-01, Financial Statements - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. See Note 2, Recent Accounting Pronouncements, in this Report for a description of how the fair value measurement is determined for loans beginning January 1, 2018.

		March 31, 2018
(Dollars in thousands)		Carrying  Amount		Fair Value		Level 1		Level 2		Level 3
Measurement Category
Fair Value
	Financial Assets
	Securities available for sale	$	4,542,486	$	4,542,486	$	—	$	4,542,486	$	—
	CRA and Community Development Investment Funds	9,801		9,801		—		9,801		—
	Mortgage loans held for sale	110,348		110,348		—		110,348		—
	Derivative instruments	17,072		17,072		—		17,072		—
	Financial Liabilities
	Derivative instruments	32,154		32,154		—		32,154		—
Amortized Cost
	Financial Assets
	Cash and cash equivalents	$	564,092	$	564,092	$	564,092	$	—	$	—
	Securities held to maturity	224,241		219,868		—		219,868		—
	Loans and leases, net of unearned income and allowance for loan and lease losses	21,561,563		21,495,639		—		—		21,495,639
	Financial Liabilities
	Deposits	22,971,192		22,970,554		—		22,970,554		—
	Short-term borrowings	900,496		900,496		525,496		375,000		—
	Long-term debt	1,449,302		1,429,335		—		—		1,429,335

47

		December 31, 2017
(Dollars in thousands)		Carrying Amount		Fair Value		Level 1		Level 2		Level 3
Measurement Category
Fair Value
	Financial Assets
	Securities available for sale	$	4,590,062	$	4,590,062	$	—	$	4,590,062	$	—
	Mortgage loans held for sale	134,916		134,916		—		134,916		—
	Derivative instruments	31,265		31,265		—		31,265		—
	Financial Liabilities
	Derivative instruments	25,154		25,154		—		25,154		—
Amortized Cost
	Financial Assets
	Cash and cash equivalents	$	625,724	$	625,724	$	625,724	$	—	$	—
	Securities held to maturity	227,318		227,964		—		227,964		—
	Loans and leases, net of unearned income and allowance for loan and lease losses	19,937,290		19,826,857		—		—		19,826,857
	Financial Liabilities
	Deposits	21,466,717		21,460,782		—		21,460,782		—
	Short-term borrowings	991,297		991,297		516,297		475,000		—
	Long-term debt	1,495,835		1,476,899		—		—		1,476,899

The fair value estimates presented herein are based upon pertinent information available to management as of March 31, 2018 and December 31, 2017. Although management is not aware of any factors that would significantly affect the estimated fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since that date and, therefore, current estimates of fair value may differ significantly from the amounts presented herein.

48

NOTE 15 – BUSINESS SEGMENTS

Each of the Company’s reportable operating segments serves the specific needs of the Company’s customers based on the products and services it offers. The reportable segments are based upon those revenue-producing components for which separate financial information is produced internally and primarily reflect the manner in which resources are allocated and performance is assessed. Further, the reportable operating segments are also determined based on the quantitative thresholds prescribed within ASC Topic 280, Segment Reporting, and consideration of the usefulness of the information to the users of the consolidated financial statements.

The Company reports the results of its operations through three reportable segments: IBERIABANK, Mortgage, and LTC. The IBERIABANK segment represents the Company’s commercial and retail banking functions, including its lending, investment, and deposit activities. IBERIABANK also includes the Company’s wealth management, capital markets, and other corporate functions. The Mortgage segment represents the Company’s origination, funding, and subsequent sale of one-to-four family residential mortgage loans. The LTC segment represents the Company’s title insurance and loan closing services.

Certain expenses not directly attributable to a specific reportable segment are allocated to segments based on pre-determined methods that reflect utilization. Also within IBERIABANK are certain reconciling items that translate reportable segment results into consolidated results. The following tables present certain information regarding our operations by reportable segment, including a reconciliation of segment results to reported consolidated results for the periods presented. Reconciling items between segment results and reported results include:

• Elimination of interest income and interest expense representing interest earned by IBERIABANK on interest-bearing checking accounts held by related companies, as well as the elimination of the related deposit balances at the IBERIABANK segment;

• Elimination of investment in subsidiary balances on certain operating segments included in total and average segment assets; and

• Elimination of intercompany due to and due from balances on certain operating segments that are included in total and average segment assets.

	Three Months Ended March 31, 2018
(Dollars in thousands)	IBERIABANK			Mortgage			LTC			Consolidated
Interest and dividend income	$	268,775		$	1,767		$	1		$	270,543
Interest expense	37,654			—			—			37,654
Net interest income	231,121			1,767			1			232,889
Provision for/(reversal of) loan and lease losses	7,991			(5		)	—			7,986
Mortgage income	—			9,595			—			9,595
Title revenue	—			—			5,027			5,027
Other non-interest income	29,906			38			—			29,944
Allocated expenses	(1,479		)	1,166			313			—
Non-interest expense	171,816			11,916			4,564			188,296
Income/(loss) before income tax expense	82,699			(1,677		)	151			81,173
Income tax expense/(benefit)	18,540			(410		)	(578		)	17,552
Net income/(loss)	$	64,159		$	(1,267	)	$	729		$	63,621
Total loans, leases, and loans held for sale, net of unearned income	$	21,652,223		$	164,215		$	—		$	21,816,438
Total assets	29,243,983			205,497			23,157			29,472,637
Total deposits	22,959,061			12,131			—			22,971,192
Average assets	27,924,587			185,742			21,890			28,132,219

49

	Three Months Ended March 31, 2017
(Dollars in thousands)	IBERIABANK			Mortgage			LTC			Consolidated
Interest and dividend income	$	190,823		$	1,709		$	1		$	192,533
Interest expense	19,715			—			—			19,715
Net interest income	171,108			1,709			1			172,818
Provision for/(reversal of) loan and lease losses	6,158			(4		)	—			6,154
Mortgage income	—			14,115			—			14,115
Title revenue	—			—			4,741			4,741
Other non-interest income	26,284			(10		)	(6		)	26,268
Allocated expenses	(2,174		)	1,656			518			—
Non-interest expense	119,429			15,167			4,200			138,796
Income/(loss) before income tax expense	73,979			(1,005		)	18			72,992
Income tax expense/(benefit)	22,829			(322		)	12			22,519
Net income/(loss)	$	51,150		$	(683	)	$	6		$	50,473
Total loans, leases, and loans held for sale, net of unearned income	$	15,072,661		$	181,874		$	—		$	15,254,535
Total assets	21,774,586			209,911			23,982			22,008,479
Total deposits	17,306,328			5,937			—			17,312,265
Average assets	21,550,930			286,694			23,877			21,861,501

50

NOTE 16 – COMMITMENTS AND CONTINGENCIES

Off-balance sheet commitments

In the normal course of business, to meet the financing needs of its customers, the Company is a party to credit-related financial instruments, with risk not reflected in the consolidated financial statements. These financial instruments include commitments to extend credit, standby letters of credit, and commercial letters of credit. Such commitments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheets. The credit policies used for these commitments are consistent with those used for on-balance sheet instruments. The Company’s exposure to credit loss in the event of non-performance by its customers under such commitments or letters of credit represents the contractual amount of the financial instruments as indicated in the table below. At both March 31, 2018 and December 31, 2017, the fair value of guarantees under commercial and standby letters of credit was $2.1 million. This fair value will decrease as the existing commercial and standby letters of credit approach their expiration dates.

At March 31, 2018 and December 31, 2017, respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Commitments to grant loans	$	319,318	$	342,305
Unfunded commitments under lines of credit	6,340,135		6,060,034
Commercial and standby letters of credit	211,070		210,002
Reserve for unfunded lending commitments	13,432		13,208

Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee by the borrower. Since many of the commitments are expected to be drawn upon, the total commitment amounts generally represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral, if any, is based on management’s credit evaluation of the customer.

Unfunded commitments under commercial lines of credit, revolving credit lines, and overdraft protection agreements are commitments for possible future extensions of credit to existing customers. Many of these types of commitments do not contain a specified maturity date and may not be drawn upon to the total extent to which the Company is committed. See Note 6, Allowance for Credit Losses and Credit Quality, for additional information related to the Company’s reserve for unfunded lending commitments.

Commercial and standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. These guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper issuance, bond financing, and similar transactions. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. When necessary they are collateralized, generally in the form of marketable securities and cash equivalents.

Legal proceedings

The nature of the business of the Company’s banking and other subsidiaries ordinarily results in a certain amount of claims, litigation, investigations, and legal and administrative cases and proceedings, which are considered incidental to the normal conduct of business. Some of these claims are against entities or assets of which the Company is a successor or acquired in business acquisitions. The Company has asserted defenses to these claims and, with respect to such legal proceedings, intends to continue to defend itself vigorously, litigating or settling cases according to management’s judgment as to what is in the best interest of the Company and its shareholders.

51

In July of 2016, the Company received a subpoena from the Office of Inspector General of the U.S. Department of Housing and Urban Development (“HUD”) requesting information on certain previously originated loans insured by the Federal Housing Administration ("FHA") as well as other documents regarding the Company's FHA-related policies and practices. After the Company complied with the subpoena, attorneys from the Department of Justice (“DOJ”) informed the Company in late March of 2017 that a civil qui tam suit had been filed against the Company in federal court involving the subject matter of the HUD subpoena. The HUD lawsuit was settled on December 11, 2017 in the amount of $11.7 million. On February 2, 2018, IBERIABANK filed a lawsuit in the United States District Court for the Eastern District of Louisiana (New Orleans) against Illinois Union Insurance Company and Travelers Casualty and Surety Company of America in an effort to recover the $11.7 million it paid to settle the HUD matter. IBERIABANK filed that lawsuit to recover the insurance proceeds to which it claims to be entitled under certain Bankers’ Professional Liability insurance policies issued by defendants Illinois Union and Travelers. More Specifically, IBERIABANK alleges that the insurers have failed to honor their obligations under the policies to pay IBERIABANK’s losses in connection with the $11.7 million settlement of disputed allegations relating to IBERIABANK’s professional services in connection with certain mortgage loans insured by the FHA.

The Company assesses its liabilities and contingencies in connection with outstanding legal proceedings utilizing the latest information available. Where it is probable that the Company will incur a loss and the amount of the loss can be reasonably estimated, the Company records a liability in its consolidated financial statements. These legal reserves may be increased or decreased to reflect any relevant developments on a quarterly basis. Where a loss is not probable or the amount of loss is not estimable, the Company does not accrue legal reserves. While the outcome of legal proceedings is inherently uncertain, based on information currently available and available insurance coverage, the Company’s management believes that it has established appropriate legal reserves. Any incremental liabilities arising from pending legal proceedings are not expected to have a material adverse effect on the Company’s consolidated financial position, consolidated results of operations, or consolidated cash flows. However, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the Company’s consolidated financial position, consolidated results of operations, or consolidated cash flows.

As of the date of this filing, the Company believes the amount of losses associated with legal proceedings that it is reasonably possible to incur above amounts already accrued is not material.

52

NOTE 17 – RELATED PARTY TRANSACTIONS

In the ordinary course of business, the Company may execute transactions with various related parties. Examples of such transactions may include lending or deposit arrangements, transfers of financial assets, services for administrative support, and other miscellaneous items.

The Company has granted loans to executive officers and directors and their affiliates. These loans, including the related principal additions, principal payments, and unfunded commitments are not material to the consolidated financial statements at March 31, 2018 and December 31, 2017. There were no outstanding loans to related parties classified as non-accrual, past due, or troubled debt restructurings at March 31, 2018.

Deposits from related parties held by the Company were not material at March 31, 2018 and December 31, 2017.

53

Item 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion and analysis is intended to assist readers in understanding the consolidated financial condition and results of operations of IBERIABANK Corporation and its wholly owned subsidiaries (collectively, the “Company”) as of and for the period ended March 31, 2018, and updates the Annual Report on Form 10-K for the year ended December 31, 2017. This discussion should be read in conjunction with the unaudited consolidated financial statements, accompanying footnotes and supplemental financial data included herein. The emphasis of this discussion will be amounts as of March 31, 2018 compared to December 31, 2017 for the balance sheets and the three months ended March 31, 2018 compared to March 31, 2017 for the statements of comprehensive income. Certain amounts in prior year presentations have been reclassified to conform to the current year presentation.

When we refer to the “Company,” “we,” “our” or “us” in this Report, we mean IBERIABANK Corporation and subsidiaries (consolidated). When we refer to the “Parent,” we mean IBERIABANK Corporation. See the Glossary of Defined Terms at the end of this Report for terms used throughout this Report.

CAUTION ABOUT FORWARD-LOOKING STATEMENTS

To the extent that statements in this Report relate to future plans, objectives, financial results or performance of the Company, these statements are deemed to be “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements, which are based on management’s current information, estimates and assumptions and the current economic environment, are generally identified by use of the words “may,” “plan,” “believe,” “expect,” “intend,” “will,” “should,” “continue,” “potential,” “anticipate,” “estimate,” “predict,” “project” or similar expressions, or the negative of these terms or other comparable terminology. The Company’s actual strategies and results in future periods may differ materially from those currently expected due to various risks and uncertainties.

Forward-looking statements represent management’s beliefs, based upon information available at the time the statements are made, with regard to the matters addressed; they are not guarantees of future performance. Forward-looking statements are subject to numerous assumptions, risks and uncertainties that change over time and could cause actual results or financial condition to differ materially from those expressed in or implied by such statements. Factors that could cause or contribute to such differences include, but are not limited to: the level of market volatility, our ability to execute our growth strategy, including the availability of future bank acquisition opportunities, our ability to execute on our revenue and efficiency improvement initiatives, unanticipated delays, losses, business disruptions and diversion of management time related to the completion and integration of mergers and acquisitions, refinements to purchase accounting adjustments for acquired businesses and assets and assumed liabilities in these transactions, adjustments of fair values of acquired assets and assumed liabilities and of deferred taxes in acquisitions, actual results deviating from the Company’s current estimates and assumptions of timing and amounts of cash flows, credit risk of our customers, effects of low energy and commodity prices, effects of residential real estate prices and levels of home sales, our ability to satisfy capital and liquidity standards, sufficiency of our allowance for loan losses, changes in interest rates, access to funding sources, reliance on the services of executive management, competition for loans, deposits and investment dollars, competition from competitors with greater financial resources than the Company, reputational risks and social factors, changes in government regulations and legislation, increases in FDIC insurance assessments, geographic concentration of our markets, economic or business conditions in our markets or nationally, rapid changes in the financial services industry, significant litigation, cyber-security risks including dependence on our operational, technological, and organizational systems and infrastructure and those of third party providers of those services, hurricanes and other adverse weather events, and valuation of intangible assets. Factors that may cause actual results to differ materially from these forward-looking statements are discussed in the Company’s Annual Report on Form 10-K and other filings with the Securities and Exchange Commission (the “SEC”), available at the SEC’s website, www.sec.gov, and the Company’s website, www.iberiabank.com, under the heading “Investor Relations” and then “Financial Information.” All information is as of the date of this Report. Except to the extent required by applicable law or regulation, the Company undertakes no obligation to revise or update publicly any forward-looking statement for any reason.

54

EXECUTIVE SUMMARY

Corporate Profile

The Company is a $29.5 billion regional financial holding company with offices in Louisiana, Arkansas, Tennessee, Alabama, Texas, Florida, Georgia, South Carolina, North Carolina, and New York offering commercial, private banking, consumer, small business, wealth and trust management, retail brokerage, mortgage, and title insurance services.

A summary of the Company's financial position and results of operations as of and for the three months ended March 31, 2018 is provided below, with further detail provided in subsequent sections of Management's Discussion and Analysis.

Results in 2018 were impacted by the following significant items:

• The Company acquired Sabadell United on July 31, 2017 for total consideration of $1.0 billion. The acquisition added $4.0 billion in loans and $4.4 billion in deposits (including approximately $0.9 billion of non-interest bearing deposits), and significantly impacted results in the first quarter of 2018 when compared to the first quarter of 2017. Acquired earning assets, offset by a lesser amount of acquired interest-bearing liabilities, resulted in higher net interest income. The acquisition benefited certain non-interest income streams, such as service charges on deposit accounts and trust department income, while additional associates and acquired locations increased salaries and employee benefits and net occupancy and equipment non-interest expenses.

• The Company acquired Gibraltar on March 23, 2018 for total consideration of $214.7 million. The acquisition added $1.5 billion in loans and $1.1 billion in deposits. The Company incurred approximately $16.2 million in pre-tax merger-related expenses during the first quarter of 2018, resulting in a $0.23 reduction to GAAP EPS. The Company successfully completed the conversion of branch and operating systems associated with the Gibraltar acquisition over the weekend of March 23-25, 2018.

• On December 22, 2017, President Trump signed the Tax Cuts and Jobs Act (the "Tax Act") into law. Among other provisions, the most significant to the Company is the reduction of the corporate income tax rate from 35% to 21%, effective January 1, 2018. The reduction in the corporate tax rate resulted in an estimated $0.17 benefit to GAAP EPS in the first quarter of 2018.

The following summarizes 1Q18 results compared to 1Q17 results:

• Net income available to common shareholders for the three months ended March 31, 2018 totaled $60.0 million, or $1.10 diluted EPS, compared to $46.9 million, or $1.00 diluted EPS, for the same period of 2017. Non-GAAP core EPS, which excludes merger-related costs and other items disclosed in Table 16 - Non-GAAP measures, was $1.37 in the first quarter of 2018 compared to $1.02 for the same period of 2017.

• Net interest income was $232.9 million for the first quarter of 2018, a $60.1 million, or 35%, increase compared to the same quarter of 2017. The increase in net interest income was primarily volume-related due to the Sabadell United acquisition, but was also impacted by higher loan yields and offset by higher funding costs, ultimately resulting in a 14 basis points increase to net interest margin on a tax-equivalent basis to 3.67% from 3.53%.

• Non-interest income decreased$0.6 million, or 1%, to $44.6 million during the quarter ended March 31, 2018, primarily due to a decrease in mortgage income, offset by increases in services charges on deposit accounts and trust department income.

• Non-interest expense for the first quarter of 2018 increased$49.5 million, or 36%, to $188.3 million compared to the same period of 2017, largely due to acquisition-related increases in salaries and employee benefits expense, net occupancy and equipment expenses, and other merger and conversion-related expenses.

• The Company recorded a provision for loan and lease losses of $8.0 million for the quarter ended March 31, 2018, a $1.8 million, or 30%, increase from the provision recorded for the same period of 2017, primarily due to loan growth over the past twelve months, as asset quality has remained stable and both non-performing assets and net charge-offs are lower than the first quarter of 2017.

• Income before income tax expense increased $8.2 million to $81.2 million for the three months ended March 31, 2018 compared to the same period of 2017; however, income tax expense decreased $5.0 million to $17.6 million for the first quarter of 2018. The decrease in income tax expense is related to the reduction of the corporate income tax rate from 35% to 21%, effective January 1, 2018. The effective tax rate was 21.6% and 30.9%, respectively, for the three months ended March 31, 2018 and 2017.

55

Summary of Financial Condition at March 31, 2018 Compared to December 31, 2017

• Total assets at March 31, 2018 were $29.5 billion, up $1.6 billion, or 6%, from December 31, 2017, primarily due to $1.6 billion assets acquired through the Gibraltar acquisition.

• Total loan growth was $1.6 billion, or 8%, in 2018, of which $1.5 billion was acquired from Gibraltar.

• Total deposits increased $1.5 billion, or 7%, in 2018, of which $1.1 billion was acquired from Gibraltar.

• Asset quality remained stable as non-performing loans to total loans remained relatively unchanged at 0.75% at March 31, 2018 compared to 0.76% at December 31, 2017.

• Shareholders’ equity increased$204.1 million, or 6%, from year-end 2017, primarily driven by the issuance of 2.8 million shares of common stock in March 2018 as part of consideration for the Gibraltar acquisition.

2018 Outlook

Management's financial guidance for 2018 provided below excludes any anticipated changes in interest rates. The guidance does include the realization of the full run-rate of non-interest expense reductions for 2018 related to the acquisitions of Sabadell United and Gibraltar; continued headwinds in the mortgage business with impact to both non-interest income and non-interest expense as operational aspects of the business are streamlined; and the impact of the previously announced $12 million expense initiative, which was completed as of March 31, 2018. Management believes that first quarter 2018 results are in-line with full year 2018 expectations.

The following further details management's expectations for 2018:

• Average earning assets of approximately $27.3 billion to $27.7 billion;

• Consolidated annualized loan growth of 15% to 17%;

• Consolidated annualized deposit growth of 17% to 21%;

• Provision expense of approximately $37 million to $42 million;

• Non-interest income, on a non-GAAP core basis, of approximately $210 million to $220 million;

• Non-interest expense, on a non-GAAP core basis, of approximately $700 million to $710 million;

• An effective tax rate of approximately 21% to 22%;

• Net interest margin of approximately 3.60% to 3.65%;

• Pre-tax one time charges of approximately $28 million to $31 million; and

• Stable credit quality.

In addition, on April 19, 2018, the Company announced its 2020 Strategic Goals, which provide financial and operating targets for Company performance to be achieved by the end of 2020.

The 2020 Strategic Goals are as follows:

• Core EPS growth of greater than 10%;

• Core Return on Average Assets of greater than 1.30%;

• Core Return on Average Tangible Common Equity of greater than 15%; and

• Core Tangible Efficiency Ratio of less than 55%.

See the Non-GAAP measures section of Management's Discussion and Analysis for a discussion of how non-GAAP core measures differ from GAAP, and how management uses these non-GAAP measures.

56

FINANCIAL OVERVIEW

The following table sets forth selected financial ratios and other relevant data used by management to analyze the Company's performance.

TABLE 1—SELECTED CONSOLIDATED FINANCIAL AND OTHER DATA

	As of and For the Three Months Ended March 31,
	2018		2017
Key Ratios (1)
Return on average assets	0.92	%	0.94	%
Core return on average assets (Non-GAAP) (2)	1.13		0.96
Return on average common equity	6.79		6.41
Core return on average tangible common equity (Non-GAAP) (2) (3)	13.83		8.99
Equity to assets at end of period	13.24		15.71
Earning assets to interest-bearing liabilities at end of period	145.28		152.09
Interest rate spread (4)	3.40		3.34
Net interest margin (TE) (4) (5)	3.67		3.53
Non-interest expense to average assets (annualized)	2.71		2.57
Efficiency ratio (6)	67.9		63.7
Core tangible efficiency ratio (TE) (Non-GAAP) (2) (3) (5) (6)	58.8		61.3
Common stock dividend payout ratio	36.0		39.0
Asset Quality Data
Non-performing assets to total assets at end of period (7)	0.64	%	1.00	%
Allowance for credit losses to non-performing loans at end of period (7)	97.35		78.47
Allowance for credit losses to total loans at end of period	0.73		1.03
Consolidated Capital Ratios
Tier 1 leverage capital ratio	9.97	%	12.91	%
Common Equity Tier 1 (CET1)	10.77		14.60
Tier 1 risk-based capital ratio	11.32		15.38
Total risk-based capital ratio	12.48		16.92

⁽¹⁾  With the exception of end-of-period ratios, all ratios are based on average daily balances during the respective periods.

⁽²⁾  See Table 16 for GAAP to Non-GAAP reconciliations.

⁽³⁾  Tangible calculations eliminate the effect of goodwill and acquisition-related intangible assets and the corresponding amortization expense on a tax-effected basis where applicable.

⁽⁴⁾  Interest rate spread represents the difference between the weighted average yield on earning assets and the weighted average cost of interest-bearing liabilities. Net interest margin represents net interest income as a percentage of average earning assets.

⁽⁵⁾  Fully taxable equivalent ("TE") calculations include the tax benefit associated with related income sources that are tax-exempt using a rate of 21% for the current quarter and 35% for prior quarters.

⁽⁶⁾  The efficiency ratio represents non-interest expense as a percentage of total revenues. Total revenues are the sum of net interest income and non-interest income.

⁽⁷⁾  Non-performing loans consist of non-accruing loans and loans 90 days or more past due. Non-performing assets consist of non-performing loans and repossessed assets.

57

ANALYSIS OF RESULTS OF OPERATIONS

Net Interest Income/Net Interest margin

Net interest income is the difference between interest realized on earning assets and interest paid on interest-bearing liabilities and is also the largest driver of earnings. As such, it is subject to constant scrutiny by management. The rate of return and relative risk associated with earning assets are weighed to determine the appropriateness and mix of earning assets. Additionally, the need for lower cost funding sources is weighed against relationships with clients and future growth opportunities. The Company’s net interest spread, which is the difference between the yields earned on average earning assets and the rates paid on average interest-bearing liabilities, was 3.40% and 3.34%, during the three months ended March 31, 2018 and 2017, respectively. The Company’s net interest margin on a taxable equivalent (“TE”) basis, which is net interest income (TE) as a percentage of average earning assets, was 3.67% and 3.53%, respectively, for the same periods.

58

The following table sets forth information regarding (i) the total dollar amount of interest income from earning assets and the resultant average yields; (ii) the total dollar amount of interest expense on interest-bearing liabilities and the resultant average rates; (iii) net interest income; (iv) net interest spread; and (v) net interest margin. Information is based on average daily balances during the indicated periods. Investment security market value adjustments and trade-date accounting adjustments are not considered to be earning assets and, as such, the net effect of these adjustments is included in non-earning assets.

TABLE 2—QUARTERLY AVERAGE BALANCES, NET INTEREST INCOME AND INTEREST YIELDS / RATES

	Three Months Ended March 31,
	2018							2017
(Dollars in thousands)	Average Balance			Interest Income/Expense (1)		Yield/ Rate (TE)(2)		Average Balance			Interest Income/Expense (1)		Yield/ Rate (TE)(2)
Earning Assets:
Loans:
Commercial loans	$	14,087,635		$	164,660	4.76	%	$	10,917,714		$	119,605	4.50	%
Residential mortgage loans	3,151,775			34,494		4.38	%	1,273,069			12,848		4.04	%
Consumer and other loans	2,941,980			38,915		5.36	%	2,854,972			36,523		5.19	%
Total loans	20,181,390			238,069		4.79	%	15,045,755			168,976		4.59	%
Loans held for sale	109,027			1,154		4.23	%	175,512			971		2.21	%
Investment securities(3)	4,843,448			28,094		2.38	%	3,741,128			19,927		2.24	%
Other earning assets	679,902			3,226		1.92	%	1,123,087			2,659		0.96	%
Total earning assets	25,813,767			270,543		4.26	%	20,085,482			192,533		3.93	%
Allowance for loan losses	(144,295		)					(145,326		)
Non-earning assets	2,462,747							1,921,345
Total assets	$	28,132,219						$	21,861,501
Interest-bearing liabilities
Deposits:
NOW accounts	$	4,363,557		$	7,081	0.66	%	$	3,239,085		$	3,090	0.39	%
Savings and money market accounts	8,664,085			14,579		0.68	%	7,211,545			8,330		0.47	%
Certificates of deposit	2,471,485			6,584		1.08	%	2,083,749			4,638		0.90	%
Total interest-bearing deposits (4)	15,499,127			28,244		0.74	%	12,534,379			16,058		0.52	%
Short-term borrowings	983,918			2,524		1.04	%	410,726			277		0.27	%
Long-term debt	1,377,323			6,886		2.03	%	618,494			3,380		2.22	%
Total interest-bearing liabilities	17,860,368			37,654		0.86	%	13,563,599			19,715		0.59	%
Non-interest-bearing demand deposits	6,278,507							4,976,945
Non-interest-bearing liabilities	275,869							221,993
Total liabilities	24,414,744							18,762,537
Shareholders’ equity	3,717,475							3,098,964
Total liabilities and shareholders’ equity	$	28,132,219						$	21,861,501
Net earning assets	$	7,953,399						$	6,521,883
Net interest income/ Net interest spread				$	232,889	3.40	%				$	172,818	3.34	%
Net interest income (TE) / Net interest margin (TE) (1)				$	234,353	3.67	%				$	175,309	3.53	%

⁽¹⁾  Interest income includes loan fees of $0.8 million and $0.7 million for the three-month periods ended March 31, 2018 and 2017, respectively.

⁽²⁾  Taxable equivalent yields are calculated using a rate of 21% for the current quarter and a rate of 35% for the prior quarter.

⁽³⁾  Balances exclude unrealized gains or losses on securities available for sale and the impact of trade date accounting.

⁽⁴⁾  Total deposit costs for the quarters ended March 31, 2018 and 2017 were 0.53% and 0.37%, respectively.

59

Net interest income increased $60.1 million to $232.9 million in the first quarter of 2018 when compared to the same quarter of 2017. Rate changes contributed to 12% of this increase while 88% was volume-driven. The primarily volume-driven increase in net interest income for the first quarter of 2018 is the result of a $5.7 billion increase in average earning assets, primarily due to the Sabadell United acquisition, and a 33 basis point increase in earning asset yield. This increase is partially offset by a $4.3 billion increase in average interest-bearing liabilities compared to the first quarter of 2017, and a 27 basis point increase in associated costs. The drivers of the increase in the earning asset yield included the repricing of variable rate legacy loans and origination coupons above existing portfolio rates, as well as improved purchase yields within the investment securities portfolio. The increase in funding costs was driven by upward repricing of indexed deposits as well as higher rates on promotional deposit offerings. In addition, funding costs also grew year-over-year as a result of the impact of the Sabadell acquisition, which included higher acquired deposit costs relative to the Company's legacy business. The yield/rate increases in late 2017 and now 2018 were impacted by the Federal Open Market Committee's interest rate increases of 25 basis points in March, June, and December of 2017. Net interest margin on a tax-equivalent basis increased 14 basis points to 3.67% from 3.53% when comparing the periods. See Table 3 below for additional information regarding the changes in net interest income.

Average loans made up 78% and 75% of average earning assets in the first quarter of 2018 and 2017. Average loans increased$5.1 billion and the associated taxable-equivalent yield increased 20 basis points when comparing the first quarter of 2018 to 2017. The increase in average loans was primarily attributable to the $4.0 billion in loans acquired through the Sabadell United acquisition. Average investment securities increased $1.1 billion when compared to the same quarter of 2017 also primarily driven by the Sabadell United acquisition.

Average interest-bearing deposits made up 87% and 92% of average interest-bearing liabilities in the first quarter of 2018 and 2017, respectively. The average balance of interest-bearing deposits increased $3.0 billion, primarily related to the Sabadell United acquisition, and the rate paid increased by 22 basis points when comparing the first quarter of 2018 to 2017. The total cost of interest-bearing liabilities rose 27 basis points when compared to the same period in prior year primarily due to increased deposit pricing and a higher rate paid on long-term FHLB advances.

60

The following table displays the dollar amount of changes in interest income and interest expense for major components of earning assets and interest-bearing liabilities. The table distinguishes between (i) changes attributable to volume (changes in average volume between periods times the average yield/rate for the two periods), (ii) changes attributable to rate (changes in average rate between periods times the average volume for the two periods), and (iii) total increase (decrease). Changes attributable to both volume and rate are allocated ratably between the volume and rate categories.

TABLE 3 - SUMMARY OF CHANGES IN NET INTEREST INCOME

	March 31, 2018
	Compared to March 31, 2017
	Change Attributable To
(Dollars in thousands)	Volume			Rate		Net Increase (Decrease)
Earning assets:
Loans:
Commercial loans	$	35,989		$	9,066	$	45,055
Residential mortgage loans	20,474			1,172		21,646
Consumer and other loans	1,244			1,148		2,392
Loans held for sale	(467		)	650		183
Investment securities	6,265			1,902		8,167
Other earning assets	(1,091		)	1,658		567
Net change in income on earning assets	62,414			15,596		78,010
Interest-bearing liabilities:
Deposits:
NOW accounts	1,322			2,669		3,991
Savings and money market accounts	2,092			4,157		6,249
Certificates of deposit	946			1,000		1,946
Borrowings	5,272			481		5,753
Net change in expense on interest-bearing liabilities	9,632			8,307		17,939
Change in net interest spread	$	52,782		$	7,289	$	60,071

Provision for Loan and Lease Losses

Management of the Company formally assesses the ACL quarterly and will make provisions for loan and lease losses and unfunded lending commitments as necessary in order to maintain the appropriateness of the ACL at the balance sheet date. The Company recorded a provision for loan and lease losses of $8.0 million for the three months ended March 31, 2018, a $1.8 million, or 30%, increase from the provision recorded for the same period of 2017. The Company’s total provision for credit losses during the three months ended March 31, 2018, which includes the provision for unfunded lending commitments recorded in non-interest expense, was $8.2 million, which was $1.6 million, or 25% above the total provision recorded in the first three months of 2017. The increase in the provision for credit losses was primarily due to loan growth over the past twelve months, as asset quality has remained stable and both non-performing assets and net charge-offs are lower than the first quarter of 2017.

See the "Asset Quality" section for further discussion on past due loans, non-performing assets, troubled debt restructurings and the allowance for credit losses.

61

Non-interest Income

The Company’s operating results for the three months ended March 31, 2018 included non-interest income of $44.6 million compared to $45.1 million for the same period of 2017. This $0.6 million decrease in non-interest income included a $4.5 milliondecrease in mortgage income. The decline in mortgage income was 59% volume-related, including a $57.5 million decline in mortgage held for sale loan originations and a $72.9 million decrease in sales volume, while reduced margins in the secondary market contributed to 41% of the decline. The Company's focus on originating mortgage loans held for sale has partially shifted with a mix of new products that entered the portfolio in 2017 and 2018. In addition, unfavorable adjustments on hedging activity on both loans held for sale and held for investment negatively impacted mortgage income during the first three months of 2018. The Company is in the process of revamping its mortgage business through recent leadership changes and hiring of mortgage loan officers. The Company believes it is well-positioned in the mortgage business for the remainder of 2018.

The decrease in mortgage income during the first quarter of 2018 compared to the first quarter of 2017 was partially offset by the following increases, primarily related to the Sabadell United acquisition:

• Service charges on deposits increased $1.8 million;

• Trust department income increased by $1.5 million; and

• Credit card and merchant-related income increased by $0.6 million.

Non-interest income as a percentage of total gross revenue (defined as total interest and non-interest income) was 14% in the first quarter of 2018 compared to 19% in the first quarter of 2017.

Non-interest Expense

The Company’s results for the first quarter of 2018 included non-interest expense of $188.3 million, an increase of $49.5 million, compared to the same quarter of 2017, largely due to merger and compensation-related expenses from acquisition activity. For the quarter, the Company’s efficiency ratio was 67.9%, compared to 63.7% in the first quarter of 2017.

Salaries and employee benefits increased $22.7 million in the first quarter of 2018 when compared to the same period of 2017. Full-time equivalent employees increased by 565 over that period, primarily related to associates brought over from the Sabadell United acquisition (and to a lesser extent, the Gibraltar and SolomonParks acquisitions), which increased compensation and related benefit expenses by $11.1 million. Severance, retention, and other merger-related compensation expenses increased $5.1 million driven by the Gibraltar acquisition. Also, in the first quarter of 2018, the Company rewarded certain associates a one-time cash bonus following the enactment of tax reform legislation, increasing bonus expense by $2.3 million. In addition, increases in merit raises, off cycle pay increases, incentive expense, and restricted stock grants also contributed to an increase in salaries and employee benefits between periods.

The following acquisition-related expense increases also occurred between the first quarter of 2017 and the first quarter of 2018:

• Data processing increased $6.0 million, primarily conversion-related;

• Errors, fines, and losses increased $6.1 million, primarily due to branch consolidations/closures;

• Net occupancy and equipment increased $4.0 million, primarily due to acquired locations;

• Amortization of acquisition intangibles increased $3.3 million;

• Professional services increased $2.1 million; and

• Insurance expenses increased $2.6 million.

Income Taxes

Income before income tax expense increased $8.2 million, or 11%, to $81.2 million for the three months ended March 31, 2018 compared to the same period of 2017; however, income tax expense decreased $5.0 million, or 22%, to $17.6 million for the first quarter of 2018. The decrease in income tax expense is related to the reduction of the corporate income tax rate from 35% to 21%, effective January 1, 2018.

The effective tax rate was 21.6% and 30.9%, respectively, for the three months ended March 31, 2018 and 2017. The difference between the Company's effective tax rates for the three months ended March 31, 2018 and 2017 and the U.S. statutory tax rates of 21% and 35%, respectively, primarily relates to tax-exempt income, non-deductible expenses, state income taxes (net of federal income tax benefit), and the recognition of tax credits.

62

FINANCIAL CONDITION

The following discussion highlights the Company’s major categories of earning assets.

Loans and Leases

The Company had total loans and leases of $21.7 billion at March 31, 2018, an increase of $1.6 billion from December 31, 2017, which includes $1.5 billion acquired in the first quarter of 2018 from Gibraltar, and supplemented by legacy loan growth of $430.8 million, or 3%. The growth in the legacy portfolio included commercial loan growth of $312.7 million, or 3%, mortgage loan growth of $104.2 million, or 9%, and consumer loan growth of $13.9 million, or 1%. In the acquired loan portfolio, pay-downs and pay-offs on loans from prior period acquisitions partially offset the acquired loans from Gibraltar. In addition, acquired loans are transferred to the legacy portfolio as they are refinanced, renewed, restructured, or otherwise underwritten to the Company's standards.

The Company’s loan to deposit ratio was 94% at both March 31, 2018 and December 31, 2017. The percentage of fixed-rate loans to total loans decreased from 41% at the end of 2017 to 40% at March 31, 2018.

The major categories of loans outstanding at March 31, 2018 and December 31, 2017 are presented in the following table.

TABLE 4—SUMMARY OF LOANS

	March 31, 2018				December 31, 2017				$ Change		% Change
(Dollars in thousands)	Balance		Mix		Balance		Mix
Commercial loans and leases:
Real estate- construction	$	1,199,625	6	%	$	1,240,396	6	%	(40,771	)	(3	)
Real estate- owner-occupied	2,612,244		12		2,529,885		12		82,359		3
Real estate- non-owner occupied	5,437,082		25		5,167,949		26		269,133		5
Commercial and industrial (1)	5,325,682		24		5,135,067		26		190,615		4
Total commercial loans and leases	14,574,633		67		14,073,297		70		501,336		4
Residential mortgage loans	3,971,067		18		3,056,352		15		914,715		30
Consumer loans:
Home equity	2,421,186		11		2,292,275		11		128,911		6
Indirect automobile	50,671		—		62,693		—		(12,022	)	(19	)
Credit card	93,261		1		96,368		1		(3,107	)	(3	)
Other	595,272		3		497,196		2		98,076		20
Total consumer loans	3,160,390		15		2,948,532		15		211,858		7
Total loans and leases	$	21,706,090	100	%	$	20,078,181	100	%	1,627,909		8

(1) Includes equipment financing leases.

Loan Portfolio Components

The Company believes its loan portfolio is diversified by product and geography throughout its footprint. With the Gibraltar acquisition, the Company added $1.5 billion of loans and expanded its presence in Southeast Florida and entered New York. Excluding acquired loans, loan growth during the first quarter of 2018 was strongest in the Corporate Asset Finance division (equipment financing business), the Energy Group (reserve-based lending) and the New Orleans market. Our Corporate Asset Finance division, which was created in 2017, grew loans and leases $75.9 million, or 28%, during the current quarter. Loans in the Houston market, which includes most energy loans, increased $78.1 million, or 4%. Our New Orleans market had growth of $36.8 million, or 2%, in the first quarter of 2018.

Commercial Loans

Total commercial loans and leases increased$501.3 million, or 4%, from December 31, 2017. Commercial loans and leases were 67% of the total portfolio at March 31, 2018 compared to 70% at December 31, 2017, primarily due to a mix-shift from the acquisition of a relatively large residential mortgage portfolio from Gibraltar. Unfunded commitments on commercial loans including approved loan commitments not yet funded were $5.2 billion at March 31, 2018, an increase of $170.8 million, or 3%, when compared to the end of the prior year.

63

Commercial real estate loans include loans to commercial customers for long-term financing of land and buildings or for land development or construction of a building. These loans are repaid from revenues through operations of the businesses, rents of properties, sales of properties and refinances. The Company’s underwriting standards generally provide for loan terms of three to seven years, with amortization schedules of generally no more than twenty-five years. Low loan-to-value ratios are generally maintained and usually limited to no more than 80% at the time of origination. The commercial real estate portfolio is comprised of approximately 13% construction loans, 28% owner-occupied loans, and 59% non-owner-occupied loans as of March 31, 2018, consistent with 14%, 28%, and 58%, respectively, at December 31, 2017. Commercial real estate loans increased$310.7 million, or 3%, during the first three months of 2018, primarily from $292.5 million in acquired Gibraltar loans.

Commercial and industrial loans and leases represent loans to commercial customers to finance general working capital needs, equipment purchases and leases and other projects where repayment is derived from cash flows resulting from business operations. The Company originates commercial business loans on a secured and, to a lesser extent, unsecured basis. The Company’s commercial business loans may be term loans or revolving lines of credit. Term loans are generally structured with terms of no more than three to seven years, with amortization schedules of generally no more than fifteen years. Commercial business term loans are generally secured by equipment, machinery or other corporate assets. The Company also provides for revolving lines of credit generally structured as advances upon perfected security interests in accounts receivable and inventory. Revolving lines of credit generally have annual maturities. The Company obtains personal guarantees of the principals as additional security for most commercial business loans. As of March 31, 2018, commercial and industrial loans and leases totaled $5.3 billion, a $190.6 million, or 4%increase, from December 31, 2017, which includes approximately $43.1 million in loans acquired from Gibraltar. Commercial and industrial loans and leases comprised 24% of the total portfolio at March 31, 2018 and 26% at December 31, 2017.

The following table details the Company’s commercial loans and leases by state.

TABLE 5—COMMERCIAL LOANS AND LEASES BY STATE OF ORIGINATION

(Dollars in thousands)	March 31, 2018		December 31, 2017		$ Change		% Change
Louisiana	$	3,488,428	$	3,472,648	15,780		—
Florida	4,942,142		4,671,023		271,119		6
Alabama	1,208,961		1,238,482		(29,521	)	(2	)
Texas	2,033,448		1,961,832		71,616		4
Georgia	1,045,446		1,023,600		21,846		2
Arkansas	704,504		704,283		221		—
Tennessee	602,146		576,538		25,608		4
New York	38,141		—		38,141		100
South Carolina and North Carolina	34,954		20,246		14,708		73
Other (1)	476,463		404,645		71,818		18
Total	$	14,574,633	$	14,073,297	501,336		4

⁽¹⁾  Other loans include primarily equipment financing and corporate asset financing leases, which the Company does not classify by state.

Residential Mortgage Loans

Residential mortgage loans consist of loans to consumers to finance a primary residence. The residential mortgage loan portfolio is comprised of non-conforming 1-4 family mortgage loans secured by properties located in the Company's market areas and originated under terms and documentation that permit their sale in a secondary market, as well as larger mortgage loans of current and prospective private banking clients. These mortgage loans are generally retained to enhance relationships, but also tend to be more profitable due to the expected shorter durations and relatively lower servicing costs associated with loans of this size. The Company does not originate or hold high loan-to-value, negative amortization, option ARM, or other exotic mortgage loans in its portfolio. The Company makes insignificant investments in loans that would be considered sub-prime (e.g., loans with a credit score of less than 620) in order to facilitate compliance with relevant Community Reinvestment Act regulations.

Total residential mortgage loans increased$914.7 million, or 30%, compared to December 31, 2017, primarily the result of approximately $929.6 million in acquired Gibraltar residential mortgage loans.

64

Consumer and Other Loans

The Company offers consumer loans in order to provide a full range of retail financial services to customers in the communities in which it operates. The Company originates substantially all of its consumer loans in its primary market areas. At March 31, 2018, $3.2 billion, or 15%, of the total loan portfolio was comprised of consumer loans, compared to $2.9 billion, or 15%, at the end of 2017.

The majority of the consumer loan portfolio is comprised of home equity loans. Home equity lending allows customers to borrow against the equity in their home and is secured by a first or second mortgage on the borrower’s residence. Real estate market values at the time the loan is secured affect the amount of credit extended. Changes in these values may impact the extent of potential losses. Home equity loans were $2.4 billion at March 31, 2018, an increase of $128.9 million from December 31, 2017. Unfunded commitments related to home equity loans and lines were $999.7 million at March 31, 2018, an increase of $86.7 million, or 9%, from the end of 2017.

All other consumer loans, which consist of credit card loans, automobile loans and other personal loans, increased $82.9 million, or 13%, from December 31, 2017, primarily from an increase of $102.3 million in other personal loans, $24.9 million of which was acquired from Gibraltar loans, partially offset by a decrease in indirect automobile loans, a product that is no longer offered.

In order to assess the risk characteristics of the loan portfolio, the Company considers the current U.S. economic environment and that of its primary market areas. See Note 6, Allowance for Credit Losses, to the unaudited consolidated financial statements for credit quality factors by loan portfolio segment.

Additional information on the Company’s consumer loan portfolio is presented in the following tables. For the purposes of Table 7, unscoreable consumer loans have been included with loans with credit scores below 660. Credit scores reflect the most recent information available as of the dates indicated.

TABLE 6—CONSUMER LOANS BY STATE OF ORIGINATION

(Dollars in thousands)	March 31, 2018		December 31, 2017		$ Change		% Change
Louisiana	$	1,106,958	$	1,119,462	(12,504	)	(1	)
Florida	980,157		805,453		174,704		22
Alabama	298,660		277,601		21,059		8
Texas	129,471		131,942		(2,471	)	(2	)
Georgia	137,031		131,910		5,121		4
Arkansas	231,903		237,627		(5,724	)	(2	)
Tennessee	85,840		89,383		(3,543	)	(4	)
New York	50,981		—		50,981		100
South Carolina and North Carolina	15		4		11		275
Other (1)	139,374		155,150		(15,776	)	(10	)
Total	$	3,160,390	$	2,948,532	211,858		7

⁽¹⁾  Other loans include primarily credit card and indirect consumer loans, which the Company does not classify by state.

TABLE 7—CONSUMER LOANS BY CREDIT SCORE

(Dollars in thousands)	March 31, 2018		December 31, 2017
Above 720	$	1,631,567	$	1,666,261
660-720	796,649		702,118
Below 660	732,174		580,153
Total consumer loans	$	3,160,390	$	2,948,532

65

Mortgage Loans Held for Sale

The Company continues to sell the majority of conforming mortgage loan originations in the secondary market rather than assume the interest rate risk associated with these longer term assets. Upon the sale, the Company retains servicing on a limited portion of these loans. Loans held for sale totaled $110.3 million at March 31, 2018, a decrease of $24.6 million, or 18%, from $134.9 million at year-end 2017. The net decrease during the first three months of 2018 is primarily due to lower sales volumes from both a seasonal slowdown in origination activity and reduced activity due to higher interest rates.

Loans held for sale have primarily been fixed-rate single-family residential mortgage loans under contracts to be sold in the secondary market. In most cases, loans in this category are sold within thirty days of closing. Buyers generally have recourse to return a purchased loan to the Company under limited circumstances. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017, for further discussion.

Investment Securities

Investment securities decreased by $50.7 million, or 1%, since December 31, 2017 to $4.8 billion at March 31, 2018, primarily due to an unfavorable market valuation on available for sale securities. Approximately 95% of the Company's investment portfolio is in available-for-sale securities, which experience unrealized losses as interest rates rise. Investment securities approximated 16% and 17% of total assets at March 31, 2018 and December 31, 2017, respectively.

All of the Company's mortgage-backed securities were issued by government-sponsored enterprises at March 31, 2018 and December 31, 2017. The Company does not hold any Fannie Mae or Freddie Mac preferred stock, corporate equity, collateralized debt obligations, collateralized loan obligations, or structured investment vehicles, nor does it hold any private label collateralized mortgage obligations, subprime, Alt-A, sovereign debt, or second lien elements in its investment portfolio. At March 31, 2018 and December 31, 2017, the Company's investment portfolio did not contain any securities that are directly backed by subprime or Alt-A mortgages.

Funds generated as a result of sales and prepayments of investment securities are used to fund loan growth and purchase other securities. The Company continues to monitor market conditions and take advantage of market opportunities with appropriate risk and return elements.

Short-term Investments

Short-term investments primarily result from excess funds invested overnight in interest-bearing deposit accounts at the FRB and the FHLB of Dallas. These balances fluctuate daily depending on the funding needs of the Company and earn interest at the current FHLB and FRB discount rates. The balance in interest-bearing deposits at other institutions increased$4.0 million, or 1%, from December 31, 2017 to $310.6 million at March 31, 2018. The Company’s cash activity is further discussed in the “Liquidity and Other Off-Balance Sheet Activities” section below.

Asset Quality

The lending activities of the Company are governed by underwriting policies established by management and approved by the Board Risk Committee of the Board of Directors. Commercial risk personnel, in conjunction with senior lending personnel, underwrite the vast majority of commercial loans. The Company provides centralized underwriting of substantially all residential mortgage, small business and consumer loans. Established loan origination procedures require appropriate documentation, including financial data and credit reports. For loans and leases secured by real property, the Company generally requires property appraisals, title insurance or a title opinion, hazard insurance, and flood insurance, where appropriate.

Loan payment performance is monitored and late charges are generally assessed on past due accounts. Delinquent and problem loans are administered by functional teams of specialized risk officers. Risk ratings on commercial exposures (as described below) are reviewed on an ongoing basis and are adjusted as necessary based on the obligor’s risk profile and debt capacity. The loan review department is responsible for independently assessing and validating risk ratings assigned to commercial exposures through a periodic sampling process.All other loans are also subject to loan reviews through a similar periodic sampling process.

66

The Company utilizes an asset risk classification system in accordance with guidelines established by the FRB as part of its efforts to monitor commercial asset quality. In connection with their examinations of insured institutions, both federal and state examiners also have the authority to identify problem assets and, if appropriate, reclassify them. There are three classifications for problem assets: “substandard,” “doubtful,” and “loss”, all of which are considered adverse classifications. Substandard assets have one or more defined weaknesses and are characterized by the distinct possibility that the Company will sustain some loss if the weaknesses are not corrected. Doubtful assets have the weaknesses of substandard assets with the additional characteristic that the weaknesses make collection or liquidation in full questionable, and there is a high probability of loss based on currently existing facts, conditions and values. An asset classified as loss is considered not collectible and of such little value that continuance as an asset of the Company is not warranted. The Company exercises judgment in determining the risk classification of its commercial exposures.

Commercial loans are placed on non-accrual status when any of the following occur: 1) the loan is maintained on a cash basis because of deterioration in the financial condition of the borrower; 2) collection of the full contractual amount of principal or interest is not expected (even if the loan is currently paying as agreed); or 3) when principal or interest has been in default for a period of 90 days or more, unless the loan is both well secured and in the process of collection. Factors considered in determining the collection of the full contractual amount of principal or interest include assessment of the borrower’s cash flow, valuation of underlying collateral, and the ability and willingness of guarantors to provide credit support.  Certain commercial loans are also placed on non-accrual status when payment is not past due and full payment of principal and interest is expected, but we have doubt about the borrower’s ability to comply with existing repayment terms. Consideration will be given to placing a loan on non-accrual due to the deterioration of the debtor’s repayment ability, the repayment of the loan becoming dependent on the liquidation of collateral, an existing collateral deficiency, the loan being classified as "Doubtful" or "Loss", the client filing for bankruptcy, and/or foreclosure being initiated. Regarding all classes within the C&I and CRE portfolios, the determination of a borrower’s ability to make the required principal and interest payments is based on an examination of the borrower’s current financial statements, industry, management capabilities, and other qualitative factors.

When a loan is placed on non-accrual status, the accrual of interest income ceases and accrued but unpaid interest is generally reversed against interest income.

Real estate acquired by the Company through foreclosure or by deed-in-lieu of foreclosure is classified as OREO, and is recorded at the lesser of the related loan balance (the pro-rata carrying value for acquired loans) or estimated fair value less costs to sell. Closed bank branches are also classified as OREO and recorded at the lower of cost or market value.

Under GAAP, certain loan modifications or restructurings are designated as TDRs. In general, the modification or restructuring of a debt constitutes a TDR if the Company, for economic or legal reasons related to the borrower’s financial difficulties, grants a concession to the borrower that the Company would not otherwise consider under current market conditions. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017 for further details.

Non-performing Assets

The Company defines non-performing assets as non-accrual loans, accruing loans more than 90 days past due, OREO, and foreclosed property. Management continuously monitors and transfers loans to non-accrual status when warranted.

The Company accounts for loans currently or formerly covered by loss sharing agreements with the FDIC, other loans acquired with deteriorated credit quality, as well as all loans acquired with significant discounts that did not exhibit deteriorated credit quality at acquisition, in accordance with ASC Topic 310-30. Collectively, all loans accounted for under ASC 310-30 are referred to as "acquired impaired loans." Application of ASC Topic 310-30 results in significant accounting differences, compared to loans originated or acquired by the Company that are not accounted for under ASC 310-30. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017 for further details.

67

Due to the significant difference in accounting for acquired impaired loans, the Company believes inclusion of these loans in certain asset quality ratios that reflect non-performing assets in the numerator or denominator (or both) results in significant distortion to these ratios. In addition, because loan-level charge-offs related to acquired impaired loans are not recognized in the financial statements until the cumulative amounts exceed the original loss projections on a pool basis, the net charge-off ratio for acquired loans is not consistent with the net charge-off ratio for other loan portfolios. The inclusion of these loans in certain asset quality ratios could result in a lack of comparability across quarters or years, and could impact comparability with other portfolios that were not impacted by acquired impaired loan accounting. The Company believes that the presentation of certain asset quality measures excluding acquired impaired loans, as indicated below, and related amounts from both the numerator and denominator provides better perspective into underlying trends related to the quality of its loan portfolio. Accordingly, the asset quality measures in the tables below present asset quality information excluding acquired impaired loans, as indicated within each table, and related amounts.

The following table sets forth the composition of the Company’s non-performing assets, including accruing loans 90 days or more past due and TDRs for the periods indicated.

TABLE 8—NON-PERFORMING ASSETS AND TROUBLED DEBT RESTRUCTURINGS

(Dollars in thousands)	March 31, 2018			December 31, 2017			$ Change	% Change
Non-accrual loans:
Commercial	$	113,793		$	111,726		2,067	2
Mortgage	19,932			17,387			2,545	15
Consumer and credit card	20,250			16,275			3,975	24
Total non-accrual loans	153,975			145,388			8,587	6
Accruing loans 90 days or more past due	8,288			6,900			1,388	20
Total non-performing loans (1) (4)	162,263			152,288			9,975	7
OREO and foreclosed property (2)	27,117			26,533			584	2
Total non-performing assets (1)	189,380			178,821			10,559	6
Performing troubled debt restructurings (3)	84,550			81,291			3,259	4
Total non-performing assets and performing troubled debt restructurings (1)	$	273,930		$	260,112		13,818	5
Non-performing loans to total loans (1) (4)	0.75		%	0.76		%
Non-performing assets to total assets (1)	0.64		%	0.64		%
Non-performing assets and performing troubled debt restructurings to total assets (1)	0.93		%	0.93		%
Allowance for credit losses to non-performing loans	97.35		%	101.19		%
Allowance for credit losses to total loans	0.73		%	0.77		%

⁽¹⁾  Non-performing loans and non-performing assets include accruing loans 90 days or more past due.

⁽²⁾  OREO and foreclosed property at March 31, 2018 and December 31, 2017 include $6.6 million and $4.5 million, respectively, of former bank properties held for development or resale.

⁽³⁾  Performing troubled debt restructurings for March 31, 2018 and December 31, 2017 exclude $72.4 million and $68.5 million, respectively, in troubled debt restructurings that meet non-performing asset criteria.

⁽⁴⁾  Non-performing loans exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans.

Total non-performing assets increased$10.6 million, or 6%, compared to December 31, 2017, as non-performing loans increased$10.0 million. Non-performing loans were 0.75% of total loans at March 31, 2018, one basis point lower than at December 31, 2017. Total non-performing assets were 0.64% of total assets at March 31, 2018, unchanged from December 31, 2017. The increase in non-accrual loans was primarily related to the movement of six relationships to non-accrual status in the first quarter of 2018, two of which were past due at December 31, 2017. Including TDRs that are in compliance with their modified terms, total non-performing assets and TDRs increased $13.8 million during the first three months of 2018.

The allowance for credit losses covered 97.3% of non-performing loans at March 31, 2018 compared to 101.2% at December 31, 2017. The Company has considered collateral support on non-performing assets in determining the allowance for credit losses.

68

At March 31, 2018, the Company had $244.2 million of commercial assets classified as substandard and $51.5 million of commercial assets classified as doubtful. Accordingly, the aggregate of the Company’s classified commercial assets was $295.7 million, or 1.00% of assets and 2.03% of total commercial loans. At December 31, 2017, classified commercial assets totaled $298.5 million, or 1.07% of assets and 2.12% of total commercial loans.

In addition to the problem loans described above, there were $200.7 million of commercial loans classified as special mention at March 31, 2018. Special mention loans are defined as loans with potential weaknesses that may, if not corrected, result in future deterioration of the loan. Special mention loans were 1.38% of total commercial loans at March 31, 2018 and 1.49% at December 31, 2017. Special mention loans at March 31, 2018 decreased $9.2 million, or 4%, from December 31, 2017, primarily from upgrades to a limited number of customer relationships during the first quarter.

Past Due and Non-accrual Loans

Past due status is based on the contractual terms of loans. Total past due and non-accrual loans were 1.11% of total loans and leases at March 31, 2018 compared to 1.07% at December 31, 2017. Additional information on past due loans and leases is presented in the following table.

TABLE 9—PAST DUE AND NON-ACCRUAL LOAN SEGREGATION

	March 31, 2018			December 31, 2017
(Dollars in thousands)	Amount		% of Outstanding Balance	Amount		% of Outstanding Balance	$ Change		% Change
Accruing:
30-59 days past due	$	61,956	0.29	$	36,818	0.18	25,138		68
60-89 days past due	16,337		0.07	24,899		0.12	(8,562	)	(34	)
90-119 days past due	7,122		0.03	5,986		0.03	1,136		19
120 days past due or more	1,166		0.01	914		0.01	252		28
	86,581		0.40	68,617		0.34	17,964		26
Non-accrual:	153,975		0.71	145,388		0.73	8,587		6
Total past due and non-accrual loans	$	240,556	1.11	$	214,005	1.07	26,551		12

⁽¹⁾  Past due and non-accrual loan amounts exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans.

Total past due and non-accrual loans increased$26.6 million from December 31, 2017 to $240.6 million at March 31, 2018. The change was due to both an $18.0 million increase in accruing loans past due and an increase of $8.6 million in non-accrual loans. The increase in accruing past due loans was primarily a result of a limited number of commercial credits that moved to 30-89 days past due at March 31, 2018. 72% of accruing loans past due were past due less than 60 days (compared to 54% at December 31, 2017).

Allowance for Credit Losses

The allowance for credit losses represents management’s best estimate of probable credit losses inherent at the balance sheet date. Determination of the allowance for credit losses involves a high degree of complexity and requires significant judgment. Several factors are taken into consideration in the determination of the overall allowance for credit losses. Based on facts and circumstances available, management of the Company believes that the allowance for credit losses was appropriate at March 31, 2018 to cover probable losses in the Company’s loan portfolio. However, future adjustments to the allowance may be necessary, and the results of operations could be adversely affected, if circumstances differ substantially from the assumptions used by management in determining the allowance for credit losses. See the “Application of Critical Accounting Policies and Estimates” and Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017 for more information.

69

The following table sets forth the activity in the Company’s allowance for credit losses for the three-month periods ended March 31, 2018 and 2017.

TABLE 10—SUMMARY OF ACTIVITY IN THE ALLOWANCE FOR CREDIT LOSSES

(Dollars in thousands)	March 31, 2018			March 31, 2017
Allowance for loan and lease losses at beginning of period	$	140,891		$	144,719
Net provision for loan and lease losses	7,986			6,154
Transfer of balance to OREO and other	(47		)	73
Loan Charge-offs	(9,116		)	(7,291		)
Recoveries	4,813			1,235
Allowance for loan and lease losses at end of period	144,527			144,890
Reserve for unfunded commitments at beginning of period	13,208			11,241
Provision for unfunded lending commitments	224			419
Reserve for unfunded lending commitments at end of period	13,432			11,660
Allowance for credit losses at end of period	$	157,959		$	156,550

The allowance for credit losses was $158.0 million at March 31, 2018, or 0.73% of total loans and leases, $3.9 million higher than at December 31, 2017. The allowance for credit losses as a percentage of loans and leases was 0.77% at December 31, 2017. The decrease in the allowance for credit losses as a percentage of loans and leases was primarily the result of the acquired Gibraltar loans, as those acquired loans are recorded at estimated fair value as of the acquisition date, which includes an estimate of expected losses in this portfolio, and as a result, no allowance for loan losses is established as of the acquisition date.

Net charge-offs during the first three months of 2018 were $4.3 million, or 0.09% of average loans and leases on an annualized basis, as compared to net charge-offs of $6.1 million, or 0.16% annualized, for the first three months of 2017. The decrease in net charge-offs was primarily the result of one commercial recovery of $3.3 million, as well as a $1.8 million reduction in gross charge-offs during the comparable periods. The provision for loan and lease losses covered 186% and 102% of net charge-offs for the first three months of 2018 and 2017, respectively.

At March 31, 2018 and December 31, 2017, the ALLL covered 89% and 93% of total non-performing loans, respectively.

FUNDING SOURCES

Deposits, both those obtained from clients in its primary market areas and those acquired through acquisitions, are the Company’s principal source of funds for use in lending and other business purposes. The Company attracts local deposit accounts by offering a wide variety of products, competitive interest rates and convenient branch office locations and service hours. Increasing core deposits is a continuing focus of the Company and has been accomplished through the development of client relationships and acquisitions. Short-term and long-term borrowings are also an important funding source for the Company. Other funding sources include subordinated debt and shareholders’ equity. Refer to the “Liquidity and Other Off-Balance Sheet Activities” section below for further discussion of the Company’s sources and uses of funding. The following discussion highlights the major changes in the mix of deposits and other funding sources during the first three months of 2018.

Deposits

The Company’s ability to attract and retain customer deposits is critical to the Company’s continued success. Total deposits increased$1.5 billion, or 7%, to $23.0 billion at March 31, 2018, from $21.5 billion at December 31, 2017, primarily driven by $1.1 billion of deposits acquired from Gibraltar in March of 2018. Excluding acquired deposits, deposit growth during 2018 was strongest in the Lake Charles, Louisiana, Naples, Florida and Mobile, Alabama markets.

70

The following table sets forth the composition of the Company’s deposits as of the dates indicated.

TABLE 11—DEPOSIT COMPOSITION BY PRODUCT

	March 31, 2018				December 31, 2017
(Dollars in thousands)	Ending Balance		Mix		Ending Balance		Mix		$ Change	% Change
Non-interest-bearing deposits	$	6,595,495	29	%	$	6,209,925	29	%	385,570	6
NOW accounts	4,500,181		19		4,348,939		20		151,242	3
Money market accounts	8,271,969		36		7,674,291		36		597,678	8
Savings accounts	874,741		4		846,074		4		28,667	3
Certificates of deposit and other time deposits	2,728,806		12		2,387,488		11		341,318	14
Total deposits	$	22,971,192	100	%	$	21,466,717	100	%	1,504,475	7

Non-interest-bearing deposits increased $385.6 million in 2018 and represented 29% of total deposits at both March 31, 2018 and December 31, 2017.

Short-term Borrowings

The Company may obtain advances from the FHLB of Dallas based upon its ownership of FHLB stock and certain pledges of its real estate loans and investment securities, provided certain standards related to the Company’s creditworthiness have been met. These advances are made pursuant to several credit programs, each of which has its own interest rate and range of maturities. The level of short-term borrowings can fluctuate significantly on a daily basis depending on funding needs and the source of funds chosen to satisfy those needs.

The Company also enters into repurchase agreements to facilitate customer transactions that are accounted for as secured borrowings. These transactions typically involve the receipt of deposits from customers that the Company collateralizes with its investment portfolio and have an average rate of 48.8 basis points.

Total short-term borrowings decreased$90.8 million, or 9%, from December 31, 2017, to $900.5 million at March 31, 2018, which included a decrease of $100.0 million in outstanding short-term FHLB advances, partially offset by an increase of $9.2 million in repurchase transactions. The decrease in short-term FHLB advances was primarily due to maturing advances and repayments of short-term FHLB advances. On a quarter-to-date average basis, short-term borrowings increased$573.2 million, or 140%, from the first quarter of 2017, primarily due to short-term FHLB advances and repurchase agreements acquired from Sabadell United in the third quarter of 2017.

Total short-term borrowings were 4% of total liabilities and 38% of total borrowings at March 31, 2018 compared to 4% and 40%, respectively, at December 31, 2017. On a quarter-to-date average basis, short-term borrowings were 4% of total liabilities and 42% of total borrowings in the first quarter of 2018, compared to 2% and 40%, respectively, during the same period of 2017.

Long-term Debt

Long-term debt decreased$46.5 million, or 3%, from December 31, 2017, to $1.4 billion at March 31, 2018, which included $405.1 million in acquired long-term FHLB advances from Gibraltar which was immediately paid off upon acquisition. In addition, the Company made an additional $246.6 million in repayments of long-term FHLB advances, partially offset by $200.0 million in proceeds from additional long-term FHLB advances in the first quarter of 2018. On a period-end basis, long-term debt was 6% of total liabilities at both March 31, 2018 and December 31, 2017.

On a quarter-to-date average basis, long-term debt increased to $1.4 billion in the first quarter of 2018, $758.8 million, or 123%, higher than the first quarter of 2017, primarily from additional long-term FHLB advances in the third and fourth quarters of 2017 to improve liquidity and to take advantage of attractive rates. Average long-term debt was 6% of average total liabilities during the first quarter of 2018 compared to 3% during the same period of 2017.

Long-term debt at March 31, 2018 included $1.3 billion in fixed-rate advances from the FHLB of Dallas that cannot be prepaid without incurring substantial penalties. The remaining debt consisted of $120.1 million of the Company’s junior subordinated debt and $44.3 million in notes payable on investments in new market tax credit entities. Interest on the junior subordinated debt is payable quarterly and may be deferred at any time at the election of the Company for up to 20 consecutive quarterly periods. During any deferral period, the Company is subject to certain restrictions, including being prohibited from declaring dividends to its common shareholders. The junior subordinated debt is redeemable by the Company in whole or in part.

71

CAPITAL RESOURCES

Common Stock

Shareholders' equity increased $204.1 million, or 6%, during the first quarter of 2018, primarily from the Company's issuance of 2.8 million shares of common stock at a price of $77.00 per common share on March 23, 2018 as part of the Gibraltar acquisition. The net increase to equity from the offering was $214.7 million. See Note 10, Shareholders' Equity, Capital Ratios, and Other Regulatory Matters, to the unaudited consolidated financial statements for more information.

The increase in shareholders' equity was also a result of undistributed income to common shareholders of $38.4 million, but was negatively impacted by a $50.8 million decrease in accumulated other comprehensive income, primarily resulting from a lower valuation of the Company's available for sale investment securities.

The Company's quarterly dividend to common shareholders was $0.38 per common share in the first quarter of 2018, compared to $0.36 in the first quarter of 2017, a 6% increase. The dividend payout ratio was 36.0% for the current quarter, down from 39.0% in the first quarter of 2017.

In 2016, the Company's Board of Directors authorized a share repurchase program of up to 950,000 shares of IBERIABANK Corporation common stock. At March 31, 2018, the remaining common shares that could be repurchased under the plan approved by the Board was 747,494 shares. Subsequent to quarter-end and through May 7, 2018, the Company repurchased 300,000 common shares for approximately $22.7 million.

Regulatory Capital

Federal regulations impose minimum regulatory capital requirements on all institutions with deposits insured by the FDIC. The FRB imposes similar capital regulations on bank holding companies. Compliance with bank and bank holding company regulatory capital requirements, which include leverage and risk-based capital guidelines, are monitored by the Company on an ongoing basis. Under the risk-based capital method, a risk weight is assigned to balance sheet and off-balance sheet items based on regulatory guidelines.

At March 31, 2018 and December 31, 2017, the Company exceeded all required regulatory capital ratios, and the regulatory capital ratios of IBERIABANK were in excess of the levels established for “well-capitalized” institutions, as shown in the following table.

TABLE 12—REGULATORY CAPITAL RATIOS

Ratio	Entity	Well- Capitalized Minimums		March 31, 2018		December 31, 2017
				Actual		Actual
Tier 1 Leverage	IBERIABANK Corporation	N/A		9.97	%	9.35	%
	IBERIABANK	5.00	%	9.83		9.10
Common Equity Tier 1 (CET1)	IBERIABANK Corporation	N/A		10.77		10.57
	IBERIABANK	6.50	%	11.16		10.86
Tier 1 risk-based capital	IBERIABANK Corporation	N/A		11.32		11.16
	IBERIABANK	8.00	%	11.16		10.86
Total risk-based capital	IBERIABANK Corporation	N/A		12.48		12.37
	IBERIABANK	10.00	%	11.83		11.55

Minimum capital ratios are subject to a capital conservation buffer. In order to avoid limitations on distributions, including dividend payments, and certain discretionary bonus payments to executive officers, an institution must hold a capital conservation buffer above its minimum risk-based capital requirements. This capital conservation buffer is calculated as the lowest of the differences between the actual CET1 ratio, Tier 1 Risk-Based Capital Ratio, and Total Risk-Based Capital ratio and the corresponding minimum ratios. At March 31, 2018, the required minimum capital conservation buffer was 1.875%, and will increase by 0.625% and fully phased-in on January 1, 2019 at 2.50%. At March 31, 2018, the capital conservation buffers of the Company and IBERIABANK were 4.48% and 3.83%, respectively. Management believes that at March 31, 2018, the Company and IBERIABANK would have met all capital adequacy requirements on a fully phased-in basis if such requirements were then effective.

72

Capital ratios at March 31, 2018 were impacted by the Gibraltar acquisition, as the common stock issued in the first quarter of 2018 resulted in an increase in our risk-based capital ratios.

LIQUIDITY AND OTHER OFF-BALANCE SHEET ACTIVITIES

Liquidity refers to the Company’s ability to generate sufficient cash flows to support its operations and to meet its obligations, including the withdrawal of deposits by customers, commitments to originate loans, and its ability to repay its borrowings and other liabilities. Liquidity risk is the risk to earnings or capital resulting from the Company’s inability to fulfill its obligations as they become due. Liquidity risk also develops from the Company’s failure to timely recognize or address changes in market conditions that affect the ability to liquidate assets in a timely manner or to obtain adequate funding to continue to operate on a profitable basis.

The primary sources of funds for the Company are deposits and borrowings. Other sources of funds include repayments and maturities of loans and investment securities, securities sold under agreements to repurchase, and, to a lesser extent, off-balance sheet borrowing availability. Certificates of deposit scheduled to mature in one year or less at March 31, 2018 totaled $1.9 billion. Based on past experience, management believes that a significant portion of maturing deposits will remain with the Company. Additionally, the majority of the investment securities portfolio is classified as available for sale, which provides the ability to liquidate unencumbered securities as needed. Of the $4.8 billion in the investment securities portfolio, $2.7 billion is unencumbered and $2.1 billion has been pledged to support repurchase transactions, public funds deposits and certain long-term borrowings. Due to the relatively short implied duration of the investment securities portfolio, the Company has historically experienced consistent cash inflows on a regular basis. Securities cash flows are highly dependent on prepayment speeds and could change materially as economic or market conditions change. 

Scheduled cash flows from the amortization and maturities of loans and securities are relatively predictable sources of funds. Conversely, deposit flows, prepayments of loan and investment securities, and draws on customer letters and lines of credit are greatly influenced by general interest rates, economic conditions, competition, and customer demand. The FHLB of Dallas provides an additional source of liquidity to make funds available for general requirements and also to assist with the variability of less predictable funding sources. At March 31, 2018, the Company had $1.7 billion of outstanding FHLB advances, $375.0 million of which was short-term and $1.3 billion was long-term. Additional FHLB borrowing capacity available at March 31, 2018 amounted to $6.7 billion. At March 31, 2018, the Company also had various funding arrangements with the Federal discount window and commercial banks providing up to $289.3 million in the form of federal funds and other lines of credit. At March 31, 2018, there were no balances outstanding on these lines and all of the funding was available to the Company.

Liquidity management is both a daily and long-term function of business management. The Company manages its liquidity with the objective of maintaining sufficient funds to respond to the predicted needs of depositors and borrowers and to take advantage of investments in earning assets and other earnings enhancement opportunities. Excess liquidity is generally invested in short-term investments such as overnight deposits. On a longer-term basis, the Company maintains a strategy of investing in various lending and investment security products. The Company uses its sources of funds primarily to fund loan commitments and to meet its ongoing commitments associated with its operations. Based on its available cash at March 31, 2018 and current deposit modeling, the Company believes it has adequate liquidity to fund ongoing operations. The Company has adequate availability of funds from deposits, borrowings, repayments and maturities of loans and investment securities to provide the Company additional working capital if needed.

ASSET/LIABILITY MANAGEMENT, MARKET RISK AND COUNTERPARTY CREDIT RISK

The principal objective of the Company’s asset and liability management function is to evaluate the Company's interest rate risk included in certain balance sheet accounts, determine the appropriate level of risk given the Company’s business focus, operating environment, capital and liquidity requirements, and performance objectives, establish prudent asset concentration guidelines and manage the risk consistent with Board approved guidelines. Through such management, the Company seeks to reduce the vulnerability of its operations to changes in interest rates. The Company’s actions in this regard are taken under the guidance of the Asset and Liability Committee. The Asset and Liability Committee normally meets monthly to review, among other things, the sensitivity of the Company’s assets and liabilities to interest rate changes, local and national market conditions, and interest rates. In connection therewith, the Asset and Liability Committee generally reviews the Company’s liquidity, cash flow needs, composition of investments, deposits, borrowings, and capital position.

73

The objective of interest rate risk management is to control the effects that interest rate fluctuations have on net interest income and on the net present value of the Company’s earning assets and interest-bearing liabilities. Management and the Board are responsible for managing interest rate risk and employing risk management policies that monitor and limit this exposure. Interest rate risk is measured using net interest income simulation and asset/liability net present value sensitivity analyses. The Company uses financial modeling to measure the impact of changes in interest rates on the net interest margin and to predict market risk. Estimates are based upon numerous assumptions including the nature and timing of interest rate levels including yield curve shape, prepayments on loans and securities, deposit decay rates, pricing decisions on loans and deposits, reinvestment/replacement of asset and liability cash flows, and others. These analyses provide a range of potential impacts on net interest income and portfolio equity caused by interest rate movements.

Included in the modeling are instantaneous parallel rate shift scenarios, which are utilized to establish exposure limits. These scenarios are known as “rate shocks” because all rates are modeled to change instantaneously by the indicated shock amount, rather than a gradual rate shift over a period of time.

The Company’s interest rate risk model indicates that the Company is asset sensitive in terms of interest rate sensitivity. Based on the Company’s interest rate risk model at March 31, 2018, the table below illustrates the impact of an immediate and sustained 100 and 200 basis points increase or decrease in interest rates on net interest income over the next twelve months.

TABLE 13—INTEREST RATE SENSITIVITY

Shift in Interest Rates (in bps)	% Change in Projected Net Interest Income
+200	1.1%
+100	0.7%
-100	(4.7)%
-200	(14.5)%

The influence of using the forward curve as of March 31, 2018 as a basis for projecting the interest rate environment would approximate a 0.5% increase in net interest income over the next 12 months. The computations of interest rate risk shown above are performed on a static balance sheet and do not necessarily include certain actions that management may undertake to manage this risk in response to unanticipated changes in interest rates and other factors to include shifts in deposit behavior.

The short-term interest rate environment is primarily a function of the monetary policy of the FRB. The principal tools of the FRB for implementing monetary policy are open market operations, or the purchases and sales of U.S. Treasury and Federal agency securities, as well as the establishment of a short-term target rate. The FRB’s objective for open market operations has varied over the years, but the focus has gradually shifted toward attaining a specified level of the Federal funds rate to achieve the long-run goals of price stability and sustainable economic growth. The Federal funds rate is the basis for overnight funding and drives the short end of the yield curve. Longer maturities are influenced by the market’s expectations for economic growth and inflation, but can also be influenced by FRB purchases and sales and expectations of monetary policy going forward.

On March 22, 2018, the Federal Open Market Committee (“FOMC”) voted to raise the target federal funds rate by 0.25% to a range of 1.50%-1.75%. The FOMC has now raised rates by one and one-half percentage points since the financial crisis in 2008, a sign of its confidence in the health of the economy. The FOMC expects that economic conditions will continue to evolve in a manner that will warrant additional gradual increases in the federal funds rate in 2018 and beyond. In addition to the FOMC increasing the target federal funds rate, the FRB also began to remove accommodation in 2017 by reducing the amount of debt held on its balance sheet. The FRB is expected to continue to wind-down its asset purchase program throughout 2018 and over the next several years. As the FOMC increases the federal funds rate and the FRB reduces its debt, it is possible that overall interest rates could rise, which may negatively impact the housing markets and the U.S. economy as a whole. In addition, deflationary pressures, while possibly lowering our operating costs, could have a significant negative effect on our borrowers, especially our business borrowers, and the values of collateral securing loans, which could negatively affect our financial performance.

The Company’s commercial loan portfolio is also impacted by fluctuations in the level of one-month LIBOR, as a large portion of this portfolio reprices based on this index, and to a lesser extent Prime. Our net interest income may be reduced if more interest-bearing liabilities than interest-earning assets reprice or mature during a period when interest rates are rising, or if more interest-earning assets than interest-bearing liabilities reprice or mature during a period when interest rates are declining.

74

The table below presents the Company’s anticipated repricing of loans and investment securities over the next four quarters.

TABLE 14—REPRICING OF CERTAIN EARNING ASSETS ⁽¹⁾ 

(Dollars in thousands)	2Q 2018		3Q 2018		4Q 2018		1Q 2019		Total less than one year
Investment securities	$	130,795	$	188,034	$	162,978	$	145,137	$	626,944
Fixed rate loans	802,697		626,988		605,916		557,678		2,593,279
Variable rate loans	10,251,176		493,140		335,888		277,361		11,357,565
Total loans	11,053,873		1,120,128		941,804		835,039		13,950,844
	$	11,184,668	$	1,308,162	$	1,104,782	$	980,176	$	14,577,788

⁽¹⁾ Amounts include expected maturities, scheduled paydowns, expected prepayments, and loans subject to floors and exclude the repricing of assets from prior periods, as well as non-accrual loans and market value adjustments.

As part of its asset/liability management strategy, the Company has seen greater levels of loan originations with adjustable or variable rates of interest in commercial and consumer loan products, which typically have shorter terms than residential mortgage loans. The majority of fixed-rate, long-term, agency-conforming residential loans are sold in the secondary market to avoid bearing the interest rate risk associated with longer duration assets in the current rate environment. However, the Sabadell and Gibraltar acquisitions brought a considerable amount of jumbo, non-agency-conforming residential mortgage loan exposure onto the balance sheet, both fixed rate and variable rate in nature, which has increased the overall duration of the portfolio. Considering all of this, as of March 31, 2018, $12.9 billion, or 60%, of the Company’s total loan portfolio had variable interest rates. The Company had no significant concentration to any single borrower or industry segment at March 31, 2018.

The Company’s strategy with respect to liabilities in recent periods has been to emphasize transaction accounts, particularly non-interest or low interest-bearing transaction accounts, which are significantly less sensitive to changes in interest rates. At March 31, 2018, 88% of the Company’s deposits were in transaction and limited-transaction accounts, compared to 89% at December 31, 2017. Non-interest-bearing transaction accounts were 29% of total deposits at both March 31, 2018 and December 31, 2017.

Much of the liquidity increase experienced in the past several years has been due to a significant increase in non-interest-bearing demand deposits. The behavior of non-interest-bearing deposits and other types of demand deposits is one of the most important assumptions used in determining the interest rate and liquidity risk positions. A loss of these deposits in the future would reduce the asset sensitivity of the Company’s balance sheet as interest-bearing funds would most likely be increased to offset the loss of this favorable funding source.

The table below presents the Company’s anticipated repricing of liabilities over the next four quarters.

TABLE 15—REPRICING OF LIABILITIES ⁽¹⁾ 

(Dollars in thousands)	2Q 2018		3Q 2018		4Q 2018		1Q 2019		Total less than one year
Time deposits	$	673,891	$	475,922	$	335,206	$	381,374	$	1,866,393
Short-term borrowings	725,496		150,000		25,000		—		900,496
Long-term debt	857,499		77,270		689		90,712		1,026,170
	$	2,256,886	$	703,192	$	360,895	$	472,086	$	3,793,059

⁽¹⁾ Amounts exclude the repricing of liabilities from prior periods.

As part of an overall interest rate risk management strategy, derivative instruments may also be used as an efficient way to modify the repricing or maturity characteristics of on-balance sheet assets and liabilities. Management may from time to time engage in such derivative instruments to effectively manage interest rate risk. These derivative instruments of the Company would modify net interest sensitivity to levels deemed appropriate.

75

IMPACT OF INFLATION OR DEFLATION AND CHANGING PRICES

The unaudited consolidated financial statements and related financial data presented herein have been prepared in accordance with GAAP, which generally require the measurement of financial position and operating results in terms of historical dollars, without considering changes in relative purchasing power over time due to inflation. Unlike most industrial companies, the majority of the Company’s assets and liabilities are monetary in nature. As a result, interest rates generally have a more significant impact on the Company’s performance than does the effect of inflation. Although fluctuations in interest rates are neither completely predictable nor controllable, the Company regularly monitors its interest rate position and oversees its financial risk management by establishing policies and operating limits. Interest rates do not necessarily move in the same direction or in the same magnitude as the prices of goods and services, since such prices are affected by inflation to a larger extent than interest rates. Although not as critical to the banking industry as to other industries, inflationary factors may have some impact on the Company’s growth, earnings, total assets and capital levels. Management does not expect inflation to be a significant factor in 2018.

Conversely, a period of deflation could affect our business, as well as all financial institutions and other industries. Deflation could lead to lower profits, higher unemployment, lower production and deterioration in overall economic conditions. In addition, deflation could depress economic activity, including loan demand and the ability of borrowers to repay loans, and consequently impair earnings through increasing the value of debt while decreasing the value of collateral for loans.

Management believes the most significant potential impact of deflation on financial results relates to the Company's ability to maintain a sufficient amount of capital to cushion against future losses. However, the Company could employ certain risk management tools to maintain its balance sheet strength in the event a deflationary scenario were to develop.

76

Non-GAAP Measures

This discussion and analysis included herein contains financial information determined by methods other than in accordance with GAAP. The Company’s management uses these non-GAAP financial measures in their analysis of the Company’s performance. Non-GAAP measures include, but are not limited to, descriptions such as core, tangible, and pre-tax pre-provision. These measures typically adjust GAAP performance measures to exclude the effects of the amortization of intangibles and include the tax benefit associated with revenue items that are tax-exempt, as well as adjust income available to common shareholders for certain significant activities or transactions that, in management’s opinion, can distort period-to-period comparisons of the Company’s performance. Transactions that are typically excluded from non-GAAP performance measures include realized and unrealized gains/losses on former bank owned real estate, realized gains/losses on securities, income tax gains/losses, merger related charges and recoveries, litigation charges and recoveries, and debt repayment penalties. Management believes presentations of these non-GAAP financial measures provide useful supplemental information that is essential to a proper understanding of the operating results of the Company’s core businesses. These non-GAAP disclosures should not be viewed as a substitute for operating results determined in accordance with GAAP, nor are they necessarily comparable to non-GAAP performance measures that may be presented by other companies. Reconciliations of GAAP to non-GAAP disclosures are presented in Table 16, with the exception of forward-looking information. The Company is unable to estimate GAAP EPS guidance without unreasonable efforts due to the nature of one-time or unusual items that cannot be predicted, and therefore has not provided this information under Regulation S-K Item 10(e)(1)(i)(B).

TABLE 16—RECONCILIATIONS OF NON-GAAP FINANCIAL MEASURES

	Three Months Ended
	March 31, 2018									March 31, 2017
(Dollars in thousands, except per share amounts)	Pre-tax			After-tax			Per share (2)			Pre-tax		After-tax		Per share (2)
Net income	$	81,173		$	63,621		$	1.17		$	72,992	$	50,473	$	1.08
Less: Preferred stock dividends	—			3,598			0.07			—		3,599		0.08
Income available to common shareholders (GAAP)	$	81,173		$	60,023		$	1.10		$	72,992	$	46,874	$	1.00
Non-interest income adjustments (1)(3):
(Gain) loss on sale of investments and other non-interest income	59			44			—			—		—		—
Non-interest expense adjustments (1)(3):
Merger-related expense	16,227			12,517			0.23			54		35		—
Compensation-related expense	1,221			928			0.02			98		63		—
Impairment of long-lived assets, net of (gain) loss on sale	2,074			1,576			0.03			1,429		929		0.02
Other non-core non-interest expense	(683		)	(520		)	(0.01		)	—		—		—
Total non-interest expense adjustments	18,839			14,501			0.27			1,581		1,027		0.02
Income tax expense (benefit) - other	—			173			—			—		—		—
Core earnings (Non-GAAP)	100,071			74,741			1.37			74,573		47,901		1.02
Provision for loan losses (1)	7,986			6,309						6,154		4,000
Pre-provision earnings, as adjusted (Non-GAAP) (3)	$	108,057		$	81,050					$	80,727	$	51,901

⁽¹⁾  Excluding preferred stock dividends, merger-related expense, and litigation expense, after-tax amounts are calculated using a tax rate of 24% in 2018 and 35% in 2017, which approximates the marginal tax rate.

⁽²⁾  Diluted per share amounts may not appear to foot due to rounding.

⁽³⁾  Adjustments to GAAP results include certain significant activities or transactions that, in management's opinion, can distort period-to-period comparisons of the Company's performance. These adjustments include, but are not limited to, realized and unrealized gains or losses on former bank-owned real estate, realized gains or losses on the sale of investment securities, merger-related expenses, litigation charges and recoveries, debt prepayment penalties, and gains, losses, and impairment charges on long-lived assets.

77

	As of and For the Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Net interest income (GAAP)	$	232,889		$	172,818
Taxable equivalent benefit	1,464			2,491
Net interest income (TE) (Non-GAAP) (1)	$	234,353		$	175,309
Non-interest income (GAAP) (3)	$	44,566		$	45,124
Taxable equivalent benefit	341			706
Non-interest income (TE) (Non-GAAP) (1) (3)	44,907			45,830
Taxable equivalent revenues (Non-GAAP) (1) (3)	279,260			221,139
Securities (gains) losses and other non-interest income	59			—
Core taxable equivalent revenues (Non-GAAP) (1) (3)	$	279,319		$	221,139
Total non-interest expense (GAAP) (3)	$	188,296		$	138,796
Less: Intangible amortization expense	5,102			1,770
Tangible non-interest expense (Non-GAAP) (2) (3)	183,194			137,026
Less: Merger-related expense	16,227			54
Compensation-related expense	1,221			98
Impairment of long-lived assets, net of (gain) loss on sale	2,074			1,429
Other non-core non-interest expense	(683		)	—
Core tangible non-interest expense (Non-GAAP)(2) (3)	$	164,355		$	135,445
Average assets (GAAP)	$	28,132,219		$	21,861,501
Less: Average intangible assets, net	1,275,889			754,723
Total average tangible assets (Non-GAAP) (2)	$	26,856,330		$	21,106,778
Total shareholders’ equity (GAAP)	$	3,900,907		$	3,457,975
Less: Goodwill and other intangibles	1,332,672			753,991
Preferred stock	132,097			132,097
Tangible common equity (Non-GAAP) (2)	$	2,436,138		$	2,571,887
Average shareholders’ equity (GAAP)	$	3,717,475		$	3,098,964
Less: Average preferred equity	132,097			132,097
Average common equity	3,585,378			2,966,867
Less: Average intangible assets, net	1,275,889			754,723
Average tangible common shareholders’ equity (Non-GAAP) (2)	$	2,309,489		$	2,212,144
Return on average assets (GAAP)	0.92		%	0.94		%
Effect of non-core revenues and expenses	0.21			0.02
Core return on average assets (Non-GAAP)	1.13		%	0.96		%
Return on average common equity (GAAP)	6.79		%	6.41		%
Effect of non-core revenues and expenses	1.66			0.14
Core return on average common equity (Non-GAAP)	8.45			6.55
Effect of intangibles (2)	5.38			2.44
Core return on average tangible common equity (Non-GAAP) (2)	13.83		%	8.99		%
Efficiency ratio (GAAP) (3)	67.9		%	63.7		%
Effect of tax benefit related to tax-exempt income (3)	(0.5		)	(0.9		)
Efficiency ratio (TE) (Non-GAAP) (1) (3)	67.4		%	62.8		%
Effect of amortization of intangibles	(1.8		)	(0.8		)
Effect of non-core items	(6.8		)	(0.7		)

78

Core tangible efficiency ratio (TE) (Non-GAAP) (1) (2) (3)	58.8		%	61.3		%
Total assets (GAAP)	$	29,472,637		$	22,008,479
Less: Goodwill and other intangibles	1,332,672			753,991
Tangible assets (Non-GAAP) (2)	$	28,139,965		$	21,254,488
Tangible common equity ratio (Non-GAAP) (2)	8.66		%	12.10		%
Cash Yield:
Earning assets average balance (GAAP)	$	25,813,767		$	20,085,482
Add: Adjustments	141,734			86,574
Earning assets average balance, as adjusted (Non-GAAP)	$	25,955,501		$	20,172,056
Net interest income (GAAP)	$	232,889		$	172,818
Add: Adjustments	(14,804		)	(10,716		)
Net interest income, as adjusted (Non-GAAP)	$	218,085		$	162,102
Yield, as reported	3.67		%	3.53		%
Add: Adjustments	(0.25		)	(0.23		)
Yield, as adjusted (Non-GAAP)	3.42		%	3.30		%

⁽¹⁾ Fully taxable-equivalent (TE) calculations include the tax benefit associated with related income sources that are tax-exempt using a rate of 35% for prior quarters and a rate of 21% for the current quarter.

⁽²⁾ Tangible calculations eliminate the effect of goodwill and acquisition-related intangibles and the corresponding amortization expense on a tax-effected basis where applicable.

⁽³⁾ Certain prior period amounts have been reclassified to conform to the net presentation requirements of ASU No. 2014-09, Revenue from Contracts with Customers, which was adopted effective January 1, 2018.

79

Glossary of Defined Terms

Term	Definition
ACL	Allowance for credit losses
Acquired loans	Loans acquired in a business combination
AFS	Securities available for sale
ALLL	Allowance for loan and lease losses
AOCI	Accumulated other comprehensive income (loss)
ASC	Accounting Standards Codification
ASU	Accounting Standards Update
Banco Sabadell	Banco de Sabadell, S.A.
Basel III	Global regulatory standards on bank capital adequacy and liquidity published by the BCBS
BCBS	Basel Committee on Banking Supervision
CET1	Common Equity Tier 1 Capital defined by Basel III capital rules
CFPB	Consumer Financial Protection Bureau
Company	IBERIABANK Corporation and Subsidiaries
Covered Loans	Acquired loans with loss protection provided by the FDIC
Dodd-Frank Act	Dodd-Frank Wall Street Reform and Consumer Protection Act
ECL	Expected credit losses
EPS	Earnings per common share
FASB	Financial Accounting Standards Board
FDIC	Federal Deposit Insurance Corporation
FHLB	Federal Home Loan Bank
FOMC	Federal Open Market Committee
FRB	Board of Governors of the Federal Reserve System
GAAP	Accounting principles generally accepted in the United States of America
Gibraltar	Gibraltar Private Bank & Trust Co.
GSE	Government-sponsored enterprises
HTM	Securities held-to-maturity
IBERIABANK	Banking subsidiary of IBERIABANK Corporation
Legacy loans	Loans that were originated directly or otherwise underwritten by the Company
LIBOR	London Interbank Borrowing Offered Rate
LTC	Lenders Title Company
MSA	Metropolitan statistical area
Non-GAAP	Financial measures determined by methods other than in accordance with GAAP
NPA	Non-performing asset
OCI	Other comprehensive income
OREO	Other real estate owned
OTTI	Other than temporary impairment
Parent	IBERIABANK Corporation
RRP	Recognition and Retention Plan
Sabadell United	Sabadell United Bank, N.A.
SolomonParks	SolomonParks Title & Escrow, LLC
SBA	Small Business Administration
SEC	Securities and Exchange Commission
TE	Fully taxable equivalent
TDR	Troubled debt restructuring
U.S.	United States of America

80

Item 3. Quantitative and Qualitative Disclosures About Market Risk

Quantitative and qualitative disclosures about market risk are presented at December 31, 2017 in Part II, Item 7A of the Company’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 23, 2018. Additional information at March 31, 2018 is included herein under Item 2, “Management’s Discussion and Analysis of Financial Condition and Results of Operations”.

Item 4. Controls and Procedures

An evaluation of the effectiveness of the Company’s disclosure controls and procedures as of March 31, 2018 was carried out under the supervision, and with the participation of, the Chief Executive Officer (“CEO”) and Chief Financial Officer (“CFO”). Based on that evaluation, the CEO and CFO have concluded that the Company’s disclosure controls and procedures are effective in alerting them in a timely manner to material information required to be disclosed by the Company in reports that it files or submits under the Securities Exchange Act of 1934 (the “Exchange Act”).

Disclosure controls and procedures are designed to ensure that information required to be disclosed in reports filed by the Company under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls are also designed with the objective of ensuring that such information is accumulated and communicated to the Company’s management, including the CEO and the CFO, as appropriate, to allow timely decisions regarding required disclosures. Disclosure controls include review of internal controls that are designed to provide reasonable assurance that transactions are properly authorized, assets are safeguarded against unauthorized or improper use and transactions are properly recorded and reported. There was no significant change in the Company’s internal controls over financial reporting during the last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the internal control over financial reporting.

Any control system, no matter how well conceived and operated, can provide only reasonable assurance that its objectives are achieved. The design of a control system inherently has limitations, including the controls’ cost relative to their benefits. Additionally, controls can be circumvented. No cost-effective control system can provide absolute assurance that all control issues and instances of fraud, if any, will be detected.

81

Part II. Other Information

Item 1. Legal Proceedings

See the "Legal Proceedings" section of "Note 16 – Commitments and Contingencies" of the Notes to the Unaudited Consolidated Financial Statements, incorporated herein by reference.

Item 1A. Risk Factors

For information regarding risk factors that could affect the Company's results of operations, financial condition and liquidity, see the risk factors disclosed in the "Risk Factors" section of the Company's Annual Report on Form 10-K for the year ended December 31, 2017, filed with the Securities and Exchange Commission on February 23, 2018.

The risk factors below relate to the acquisition of Gibraltar Private Bank & Trust Co., which we refer to as "Gibraltar," and are in addition to the risk factors previously disclosed in the Company's Annual Report on Form 10-K for the year ended December 31, 2017. The Company completed its acquisition of Gibraltar on March 23, 2018.

We may fail to realize all of the anticipated benefits of the Gibraltar Acquisition.

The success of the recently completed acquisition will depend, in part, on our ability to realize the anticipated benefits and cost savings from combining our business with the business of Gibraltar. If we are not able to achieve these objectives, the anticipated benefits and cost savings of the Gibraltar Acquisition may not be realized fully or at all or may take longer to realize than expected.

We have incurred significant transaction and acquisition-related integration costs in connection with the Gibraltar Acquisition.

We have incurred significant costs associated with completing the Gibraltar Acquisition and integrating Gibraltar’s operations, and are continuing to assess the impact of these costs. Although we believe that the elimination of duplicate costs, as well as the realization of other efficiencies related to the integration of Gibraltar’s business, will offset incremental transaction and merger-related costs over time, this net benefit may not be achieved in the near term, or at all.

82

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

On May 4, 2016, IBERIABANK Corporation's Board of Directors authorized the repurchase of up to 950,000 shares of the Company's outstanding common stock. Stock repurchases under this program will be made from time to time, on the open market or in privately negotiated transactions. The timing of these repurchases will depend on market conditions and other requirements. The Company anticipates the share repurchase program will extend over a two-year time frame, or earlier if the shares have been repurchased. The share repurchase program does not obligate the Company to repurchase any dollar amount or number of shares, and the program may be extended, modified, suspended, or discontinued at any time. For additional information, see the Company’s Current Report on Form 8-K/A (Amendment No. 2) filed with the SEC on October 11, 2017, which is incorporated herein by reference.

The Company did not repurchase any shares during the quarter ended March 31, 2018. At March 31, 2018, the remaining common shares that could be repurchased under the plan approved by the Board was 747,494 shares. Subsequent to quarter-end and through May 7, 2018, the Company repurchased 300,000 common shares for approximately $22.7 million.

Restrictions on Dividends and Repurchase of Stock

Holders of IBERIABANK Corporation common stock are only entitled to receive such dividends as the Company's Board of Directors may declare out of funds legally available for such payments. Furthermore, holders of IBERIABANK Corporation common stock are subject to the prior dividend rights of any holders of the Company's preferred stock then outstanding. There were 13,750 shares of preferred stock outstanding at March 31, 2018.

IBERIABANK Corporation understands the importance of returning capital to shareholders. Management will continue to execute the capital planning process, including evaluation of the amount of the common stock dividend, with the Board of Directors and in conjunction with the regulators, subject to the Company's results of operations. Also, IBERIABANK Corporation is a bank holding company, and its ability to declare and pay dividends is dependent on certain federal regulatory considerations, including the guidelines of the Federal Reserve regarding capital adequacy and dividends.

Item 3. Defaults Upon Senior Securities

Not Applicable.

Item 4. Mine Safety Disclosures

Not Applicable.

Item 5. Other Information

None.

83

Item 6. Exhibits

Exhibit No. 31.1	Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
Exhibit No. 31.2	Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
Exhibit No. 32.1	Certification of Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
Exhibit No. 32.2	Certification of Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
Exhibit No. 101.INS	XBRL Instance Document.
Exhibit No. 101.SCH	XBRL Taxonomy Extension Schema.
Exhibit No. 101.CAL	XBRL Taxonomy Extension Calculation Linkbase.
Exhibit No. 101.DEF	XBRL Taxonomy Extension Definition Linkbase.
Exhibit No. 101.LAB	XBRL Taxonomy Extension Label Linkbase.
Exhibit No. 101.PRE	XBRL Taxonomy Extension Presentation Linkbase.

84

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	IBERIABANK Corporation
Date: May 8, 2018	By:	/s/ Daryl G. Byrd
	Daryl G. Byrd
	President and Chief Executive Officer
Date: May 8, 2018	By:	/s/ Anthony J. Restel
	Anthony J. Restel
	Vice Chairman and Chief Financial Officer

85

EX-31.1

EXHIBIT 31.1

CERTIFICATIONS

SECTION 302 CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

I, Daryl G. Byrd, President and Chief Executive Officer of IBERIABANK Corporation, certify that:

1. I have reviewed this quarterly report on Form 10-Q of IBERIABANK Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of the annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date:	May 8, 2018	/s/ Daryl G. Byrd
		Daryl G. Byrd
		President and Chief Executive Officer

EX-31.2

EXHIBIT 31.2

CERTIFICATIONS

SECTION 302 CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

I, Anthony J. Restel, Vice Chairman and Chief Financial Officer of IBERIABANK Corporation, certify that:

1. I have reviewed this quarterly report on Form 10-Q of IBERIABANK Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of the annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date:	May 8, 2018	/s/ Anthony J. Restel
		Anthony J. Restel
		Vice Chairman and Chief Financial Officer

EX-32.1

EXHIBIT 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of IBERIABANK Corporation (the “Company”) on Form 10-Q for the period ended March 31, 2018 (the “Report”), I, Daryl G. Byrd, President and Chief Executive Officer of the Company, certify that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company as of and for the periods covered in the Report.

Date:	May 8, 2018	/s/ Daryl G. Byrd
		Daryl G. Byrd
		President and Chief Executive Officer

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request. The information furnished herein shall not be deemed to be filed for purposes of Section 18 of the Securities Exchange Act of 1934, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933.

EX-32.2

EXHIBIT 32.2

CERTIFICATION OF CHIEF FINANCIAL OFFICER PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of IBERIABANK Corporation (the “Company”) on Form 10-Q for the period ended March 31, 2018 (the “Report”), I, Anthony J. Restel, Vice Chairman and Chief Financial Officer of the Company, certify that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company as of and for the periods covered in the Report.

Date:	May 8, 2018	/s/ Anthony J. Restel
		Anthony J. Restel
		Vice Chairman and Chief Financial Officer

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request. The information furnished herein shall not be deemed to be filed for purposes of Section 18 of the Securities Exchange Act of 1934, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933.

XML

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Trading Symbol	IBKC
Entity Registrant Name	IBERIABANK CORP
Entity Central Index Key	0000933141
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		56,648,939

XML

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and due from banks	$ 253,527	$ 319,156
Interest-bearing deposits in banks	310,565	306,568
Total cash and cash equivalents	564,092	625,724
Securities available for sale, at fair value	4,542,486	4,590,062
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	224,241	227,318
Mortgage loans held for sale, at fair value	110,348	134,916
Loans and leases, net of unearned income	21,706,090	20,078,181
Allowance for loan and lease losses	(144,527)	(140,891)
Loans and leases, net	21,561,563	19,937,290
Premises and equipment, net	329,454	331,413
Goodwill	1,236,169	1,188,902
Other intangible assets	102,404	88,562
Other assets	801,880	779,942
Total Assets	29,472,637	27,904,129
Deposits:
Non-interest-bearing	6,595,495	6,209,925
Interest-bearing	16,375,697	15,256,792
Total deposits	22,971,192	21,466,717
Short-term borrowings	900,496	991,297
Long-term debt	1,449,302	1,495,835
Other liabilities	250,740	253,489
Total Liabilities	25,571,730	24,207,338
Shareholders’ Equity
Preferred stock	132,097	132,097
Common stock, $1 par value - 100,000,000 shares authorized; 56,778,841 and 53,872,272 shares issued and outstanding, respectively	56,779	53,872
Additional paid-in capital	3,001,389	2,787,484
Retained earnings	807,325	769,226
Accumulated other comprehensive income (loss)	(96,683)	(45,888)
Total Shareholders’ Equity	3,900,907	3,696,791
Total Liabilities and Shareholders’ Equity	$ 29,472,637	$ 27,904,129

XML

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Securities held to maturity, fair values	$ 219,868	$ 227,964
Preferred stock, par value (in usd per share)	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Liquidation preference (per share)	$ 10,000	$ 10,000
Preferred stock, shares issued	13,750	13,750
Preferred stock, shares outstanding	13,750	13,750
Common stock, par value (in usd per share)	$ 1	$ 1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	56,778,841	53,872,272
Common stock, shares outstanding	56,778,841	53,872,272

XML

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest and Dividend Income
Loans, including fees	$ 238,069	$ 168,976
Mortgage loans held for sale, including fees	1,154	971
Investment securities:
Taxable interest	25,328	17,864
Tax-exempt interest	2,766	2,063
Other	3,226	2,659
Total interest and dividend income	270,543	192,533
Deposits:
NOW and MMDA	21,228	11,100
Savings	432	320
Time deposits	6,584	4,638
Short-term borrowings	2,524	277
Long-term debt	6,886	3,380
Total interest expense	37,654	19,715
Net interest income	232,889	172,818
Provision for loan and lease losses	7,986	6,154
Net interest income after provision for loan and lease losses	224,903	166,664
Non-interest Income
Mortgage income	9,595	14,115
Service charges on deposit accounts	12,908	11,153
Title revenue	5,027	4,741
Broker commissions	2,221	2,547
ATM/debit card fee income	2,633	2,483
Credit card and merchant-related income	2,907	2,298
Trust Department Income	3,426	1,912
Income from bank owned life insurance	1,282	1,311
Gain (loss) on sale of available for sale securities	(59)	0
Other non-interest income	4,626	4,564
Total non-interest income	44,566	45,124
Non-interest Expense
Salaries and employee benefits	104,586	81,853
Net occupancy and equipment	20,047	16,021
Communication and delivery	3,902	3,044
Marketing and business development	4,752	3,424
Data processing	12,393	6,362
Professional services	7,391	5,335
Credit and other loan related expense	4,618	4,526
Insurance	7,105	4,529
Travel and entertainment	3,237	2,484
Amortization of Intangible Assets	5,102	1,770
Errors, fines, and losses	8,757	2,658
Other non-interest expense	6,406	6,790
Total non-interest expense	188,296	138,796
Income before income tax expense	81,173	72,992
Income tax expense	17,552	22,519
Net Income	63,621	50,473
Less: Preferred stock dividends	3,598	3,599
Net Income Available to Common Shareholders	60,023	46,874
Less: Earnings allocated to unvested restricted stock	639	346
Earnings allocated to common shareholders	$ 59,384	$ 46,528
Earnings per common share - Basic (in usd per share)	$ 1.11	$ 1.01
Earnings per common share - Diluted (in usd per share)	1.10	1.00
Cash dividends declared per common share (in usd per share)	$ 0.38	$ 0.36
Comprehensive Income
Net income	$ 63,621	$ 50,473
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during the period (net of tax effects of $14,223 and $2,421, respectively)	(53,506)	4,496
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $13 and $0, respectively)	(46)	0
Unrealized gains (losses) on securities, net of tax	(53,460)	4,496
Fair value of derivative instruments designated as cash flow hedges:
Change in fair value of derivative instruments designated as cash flow hedges during the period (net of tax effects of $678 and $39, respectively)	2,549	73
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $31 and $24, respectively)	(116)	(45)
Fair value of derivative instruments designated as cash flow hedges, net of tax	2,665	118
Other comprehensive income (loss), net of tax	(50,795)	4,614
Comprehensive income	$ 12,826	$ 55,087

XML

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Unrealized holding gains (losses), taxes	$ 14,223	$ 2,421
Reclassification adjustment for gains (losses) included in net income, taxes	13	0
Change in fair value of derivative instruments designated as cash flow hedges, taxes	678	39
Reclassification adjustment for gains (losses) included in net income, taxes	$ 31	$ 24

XML

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2016		13,750	44,795,386
Beginning balance at Dec. 31, 2016	$ 2,939,694	$ 132,097	$ 44,795	$ 2,084,446	$ 704,391	$ (26,035)
Increase (Decrease) in Shareholders' Equity
Net income	50,473				50,473
Other comprehensive income/(loss)	4,614					4,614
Cash dividends declared	(18,271)				(18,271)
Preferred stock dividends	(3,599)				(3,599)
Common stock issued under incentive plans, net of shares surrendered in payment, including tax benefit (in shares)			74,522
Common stock issued under incentive plans, net of shares surrendered in payment	(3,851)		$ 75	(3,926)
Shares issued (in shares)			6,100,000
Common stock issued			$ 6,100	479,094
Preferred Stock Issued During Period, Value, New Issues	485,194
Share-based compensation cost	3,721			3,721
Ending balance (in shares) at Mar. 31, 2017		13,750	50,969,908
Ending balance at Mar. 31, 2017	3,457,975	$ 132,097	$ 50,970	2,563,335	732,994	(21,421)
Beginning balance (in shares) at Dec. 31, 2017		13,750	53,872,272
Beginning balance at Dec. 31, 2017	3,696,791	$ 132,097	$ 53,872	2,787,484	769,226	(45,888)
Increase (Decrease) in Shareholders' Equity
Net income	63,621				63,621
Other comprehensive income/(loss)	(50,795)					(50,795)
Cash dividends declared	(21,579)				(21,579)
Preferred stock dividends	(3,598)				(3,598)
Common stock issued under incentive plans, net of shares surrendered in payment, including tax benefit (in shares)			118,796
Common stock issued under incentive plans, net of shares surrendered in payment	(2,581)		$ 119	(2,700)
Stock Issued During Period, Shares, Acquisitions			2,787,773
Stock Issued During Period, Value, Acquisitions	214,659		$ 2,788	211,871
Share-based compensation cost	4,734			4,734
Ending balance (in shares) at Mar. 31, 2018		13,750	56,778,841
Ending balance at Mar. 31, 2018	$ 3,900,907	$ 132,097	$ 56,779	$ 3,001,389	$ 807,325	$ (96,683)

XML

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash dividends declared per common share (in usd per share)	$ 0.38	$ 0.36
Retained Earnings
Cash dividends declared per common share (in usd per share)	$ 0.38	$ 0.36

XML

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flows from Operating Activities
Net income	$ 63,621	$ 50,473
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion, including amortization of purchase accounting adjustments and market value adjustments	(309)	1,646
Provision for loan and lease losses	7,986	6,154
Share-based compensation cost - equity awards	4,734	3,721
Loss/(gain) on sale of OREO and long-lived assets, net of impairment	670	(746)
Loss/(gain) on sale of available for sale securities	59	0
Expense/(benefit) for deferred income taxes	10,992	(10,565)
Originations of mortgage loans held for sale	(336,400)	(393,924)
Proceeds from sales of mortgage loans held for sale	367,487	440,337
Realized and unrealized (gain)/loss on mortgage loans held for sale, net	(9,320)	(13,689)
Other operating activities, net	(13,113)	(20,933)
Net Cash Provided by Operating Activities	96,407	62,474
Cash Flows from Investing Activities
Proceeds from maturities, prepayments and calls of available for sale securities	149,987	113,940
Purchases of available for sale securities, net of available for sale securities acquired	(194,543)	(491,055)
Proceeds from maturities, prepayments and calls of held to maturity securities	2,288	2,968
Purchases of equity securities, net of equity securities acquired	(2,452)	(200)
Proceeds from sales of equity securities	61,038	0
Increase in loans, net of loans acquired	(145,201)	(60,609)
Proceeds from sales of premises and equipment	1,408	7
Purchases of premises and equipment, net of premises and equipment acquired	(5,798)	(2,761)
Proceeds from dispositions of OREO	5,318	4,374
Cash paid for additional investment in tax credit entities	(750)	(795)
Payments to Acquire Businesses, Net of Cash Acquired	99,312	0
Other investing activities, net	(745)	6,327
Net Cash Used in Investing Activities	(30,138)	(427,804)
Cash Flows from Financing Activities
Increase/(decrease) in deposits, net of deposits acquired	440,470	(95,916)
Net change in short-term borrowings	(90,802)	(60,440)
Proceeds from long-term debt, net of long-term debt acquired	200,227	0
Repayments of long-term debt	(651,684)	(622)
Cash dividends paid on common stock	(19,933)	(16,126)
Cash dividends paid on preferred stock	(3,598)	(3,599)
Net share-based compensation stock transactions	(2,581)	(4,169)
Net proceeds from issuance of common stock	0	485,194
Net Cash Used in Financing Activities	(127,901)	304,322
Net Increase (Decrease) In Cash and Cash Equivalents	(61,632)	(61,008)
Cash and Cash Equivalents at Beginning of Period	625,724	1,362,126
Cash and Cash Equivalents at End of Period	564,092	1,301,118
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	1,757	2,733
Common stock issued in acquisitions	214,659	0
Cash paid for:
Interest on deposits and borrowings	37,035	19,850
Income taxes, net	$ 101	$ 39,609

XML

Basis of Presentation

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Basis of Presentation

BASIS OF PRESENTATION

General

IBERIABANK Corporation is a regional financial holding company with offices in Louisiana, Arkansas, Tennessee, Alabama, Texas, Florida, Georgia, South Carolina, North Carolina, and New York offering commercial, private banking, consumer, small business, wealth and trust management, retail brokerage, mortgage, and title insurance services. The consolidated financial statements include the accounts of the Company and its subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Certain amounts reported in prior periods have been reclassified to conform to the current period presentation. These reclassifications did not have a material effect on previously reported consolidated financial statements.

The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all information or footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting of normal and recurring items, necessary for a fair presentation of the consolidated financial statements have been made. These interim financial statements should be read in conjunction with the audited consolidated financial statements and footnote disclosures for the Company previously filed with the SEC in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Operating results for the period ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018.

When we refer to the “Company,” “we,” “our,” or “us” in this Report, we mean IBERIABANK Corporation and subsidiaries (consolidated). When we refer to the “Parent,” we mean IBERIABANK Corporation. See the Glossary of Defined Terms at the end of this Report for terms used throughout this Report.

Concentrations of Credit Risk

Most of the Company’s business activity is with customers located in the southeastern United States. The Company’s lending activity is concentrated in its market areas within those states. The Company has emphasized originations of commercial loans and private banking loans, defined as loans to higher net worth clients. Repayments on loans are expected to come from cash flows of the borrower and/or guarantor. Losses on secured loans are limited by the net realizable value of the collateral upon default of the borrowers and guarantor support. The Company believes it does not have any excessive concentrations to any one industry, loan type, or customer.

XML

Recent Accounting Pronouncements (Notes)

3 Months Ended

Mar. 31, 2018

Accounting Changes and Error Corrections [Abstract]

New Accounting Pronouncements and Changes in Accounting Principles [Text Block]

RECENT ACCOUNTING PRONOUNCEMENTS

Pronouncements adopted during the three months ended March 31, 2018:

ASU No. 2014-09

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which implements a common revenue standard and clarifies the principles used for recognizing revenue. The amendments in the ASU clarify that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.

Revenue from Contracts with Customers

The majority of the Company’s income streams (e.g., interest and dividend income and mortgage income) are accounted for in accordance with GAAP literature outside the scope of ASC 606, Revenue from Contracts with Customers. Details regarding income recognition for interest and non-interest streams can be found throughout the Company’s 2017 10-K (including Note 1 - Summary of Significant Accounting Policies). Impairment losses recognized against certain receivables (e.g., NSF fees) and capitalized costs (e.g., sales commissions) associated with contracts within the scope of ASC 606 are immaterial.

Non-interest income from service charges on deposit accounts, broker commissions, ATM/debit card fee income, credit card and merchant-related income (e.g., interchange fees), and transactional income from traditional banking services (part of other non-interest income) are the significant income streams within the scope of ASC 606 associated with the IBERIABANK reportable segment. Non-interest income from title revenue is associated with the LTC reportable segment.

Recognition of Revenue from Contracts with Customers

The Company enters into various contracts with customers to provide traditional banking services, including asset management, on a routine basis. The Company’s performance obligations are generally service-related and provided on a daily or monthly basis. The Company does not typically have performance obligations which extend beyond a reporting period. The performance obligations are generally satisfied upon completion of service (i.e., as services are rendered) and the fees are collected at such time, or shortly thereafter. The fees are readily determinable and allocated individually to each service. It is not typical for contracts to require significant judgment to determine the transaction price. Some contracts contain variable consideration; however, the variable consideration is generally constrained (not estimable) as it is based on the occurrence or nonoccurence of a contingent event (or another constraint in some circumstances). The Company generally records the variable consideration when the contingent event occurs and the fee is determinable.

The Company provides some services for customers in which it acts in an agent capacity, but generally acts in a principal capacity. Payment terms and conditions vary slightly amongst services; however, amounts are generally invoiced and due or collected by the Company within 30 days, although some fees may be prepaid. The Company bills the customer periodically as performance obligations are satisfied for most services. Therefore, revenue for services provided is generally recognized in the amount invoiced (except in circumstances of prepayment) as that amount corresponds directly to the value of the Company’s performance. In the normal course of business, the Company does not generally grant refunds for services provided. As such, the Company does not establish provisions for estimated returns.

Title revenue associated with services provided by LTC, as well as broker commissions, ATM/debit card fee income, credit card and merchant-related income (e.g., interchange fees), and transactional fees from traditional banking services generated within IBERIABANK are generally recognized at the point-in-time the services are provided. The Company has determined this recognition to be appropriate as, upon completion of services, the Company has completed its performance obligations, has a present right to payment (or has collected the cash), and the customer is able to obtain (or has obtained) substantially all of the benefits from the performance obligation (i.e., the provided services). Revenues from service charges on deposit accounts are recognized at the end of the monthly service period (e.g., account service charges) or the date the performance obligation is satisfied (e.g., NSF, stop payment, wire transfer, etc.), except for deposit account services performed by Treasury Management which are recognized on a monthly basis, as these services are performed over that time. Asset management fees (e.g., trust fees) are generally recognized at the end of the monthly service period, but fees are not collected until the beginning of the subsequent month, although some contracts may have quarterly terms and/or be prepaid. NSF fees which are not initially paid are subsequently recorded as “loans” (along with the overdraft balance) and remain classified as such until the amount is paid or charged-off (generally after 60 days).

Adoption of ASC 606

The Company adopted ASC 606 as of January 1, 2018 for all contracts as of the effective date. Prior period amounts have been reclassified to conform to current guidance requirements related to the net presentation of certain costs associated with interchange fees and rewards programs. The reclassification of prior period amounts reduced non-interest income and non-interest expense by an immaterial amount (approximately $2.2 million for the three months ended March 31, 2017) and had no impact on net income. There was no cumulative adjustment made to opening retained earnings as of January 1, 2018.

ASU No. 2016-01

In January 2016, the FASB issued ASU No. 2016-01, Financial Statements - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, which impacts how the Company measures certain equity investments and discloses and presents certain financial instruments through the application of the “exit price” notion.

The Company adopted the amendments beginning January 1, 2018. Under the new guidance, equity investments can no longer be classified as trading or available for sale (AFS), and related unrealized holding gains and losses can no longer be recognized in OCI. Per the ASU, such equity investments should be measured at fair value, with adjustments recognized in earnings at the end of each reporting period. As such, the Company reclassified its portfolio of equity investments (approximately $9.8 million at March 31, 2018) previously classified as AFS investment securities to “other assets.” As these equity investments were previously measured at fair value, implementation of the ASU did not impact the Company’s valuation method. In accordance with the ASU, the cumulative-effect adjustment from AOCI to retained earnings for previously recorded fair value adjustments related to these equity investments at adoption was insignificant.

The Company elected the practical expedient measurement alternative to prospectively account for other equity investments that do not have readily determinable fair values at cost less impairment plus or minus observable price changes in orderly transactions for an identical or similar investment of the same issuer. These investments are immaterial overall and are classified within “other assets” on the Company’s consolidated balance sheets.

The Company also modified its fair value methodology for loans measured at amortized cost whose fair values were previously disclosed using an “entry price” methodology to an “exit price” methodology, in accordance with the ASU. The Company’s “exit price” methodology estimates the fair value of these loans based on the present value of the future cash flows using the interest rate that would be charged for a similar loan to a borrower with similar risk at the indicated balance sheet date, adjusted for a liquidity discount based on the estimated time period to complete a sale transaction with a market participant. This change in methodology solely impacted the Company’s disclosures, and had no impact to the Company’s consolidated financial statements.

ASU No. 2016-15

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (ASC 230): Classification of Certain Cash Receipts and Cash Payments, in order to reduce current diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows.

The Company retrospectively adopted the amendments effective January 1, 2018. The adoption of these amendments did not impact the Company’s consolidated statements of cash flows.

ASU No. 2017-12

In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities, which amends the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements and enhance the transparency and understandability of hedge results.

The Company elected to early adopt the amendments effective January 1, 2018. The modified-retrospective adoption of the amendments did not impact the Company’s consolidated financial statements in the current or prior periods.

Pronouncements issued but not yet adopted:

ASU No. 2016-02

In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842). A significant amendment to existing GAAP from this ASU is the recognition of lease assets (i.e., right of use assets) and liabilities on the balance sheet for leases that are classified as operating leases by lessees. The lessor model remains similar to the current accounting model in existing GAAP. Additional amendments include, but are not limited to, the elimination of leveraged leases; modification to the definition of a lease; amendments on sale and leaseback transactions; and disclosure of additional quantitative and qualitative information.

ASU 2016-02 will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. Lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company will adopt the amendments on January 1, 2019.

The Company occupies certain banking offices and equipment under operating lease agreements, which currently are not recognized on the consolidated balance sheets. Based on the Company’s preliminary analysis of its current portfolio, the impact to the Company’s consolidated balance sheets is estimated to result in less than a 1% increase in assets and liabilities. The Company is also currently assessing the practical expedients it may elect at adoption, the final determination of the incremental borrowing rate, and the impact to regulatory capital ratios, amongst other matters associated with the ASU.

The adjustment to retained earnings is not expected to be significant based on the transition guidance associated with current sale-leaseback agreements. The Company also anticipates additional disclosures to be provided at adoption.

ASU No. 2016-13

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments. The amendments introduce an impairment model that is based on expected credit losses (“ECL”), rather than incurred losses, to estimate credit losses on certain types of financial instruments (e.g., loans and held-to-maturity securities), including certain off-balance sheet financial instruments (e.g., loan commitments). The measurement of ECL should consider historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments, over the contractual term. Financial instruments with similar risk characteristics may be grouped together when estimating ECL.

The ASU also amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset through the use of an allowance to record estimated credit losses (and subsequent recoveries). Non-credit related losses will continue to be recognized through OCI.

In addition, the amendments provide for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination. The initial estimate of expected credit losses would be recognized through an ALLL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition.

ASU 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods. The amendments will be applied through a modified-retrospective approach, resulting in a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. A prospective transition approach is required for debt securities for which OTTI had been recognized before the effective date. Amounts previously recognized in AOCI as of the date of adoption that relate to improvements in cash flows expected to be collected should continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption should be recorded in earnings when received.

The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements; however, the Company has engaged third-party consultants to assist with the ASU and has developed an implementation plan.

XML

Loans

3 Months Ended

Mar. 31, 2018

Receivables [Abstract]

Loans

LOANS AND LEASES

Loans and leases consist of the following for the periods indicated:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Commercial loans and leases:
Real estate- construction	$	1,199,625	$	1,240,396
Real estate- owner-occupied	2,612,244		2,529,885
Real estate- non-owner-occupied	5,437,082		5,167,949
Commercial and industrial (1)	5,325,682		5,135,067
	14,574,633		14,073,297
Residential mortgage loans:	3,971,067		3,056,352
Consumer loans:
Home equity	2,421,186		2,292,275
Indirect automobile	50,671		62,693
Credit card	93,261		96,368
Other	595,272		497,196
	3,160,390		2,948,532
Total	$	21,706,090	$	20,078,181

⁽¹⁾  Includes equipment financing leases.

Net deferred loan origination fees were $31.4 million and $29.3 million at March 31, 2018 and December 31, 2017, respectively. Total net discount on the Company's loans was $158.1 million and $159.3 million at March 31, 2018 and December 31, 2017, respectively, of which $100.8 million and $94.7 million was related to non-impaired loans. Net loan discounts include preliminary discounts recorded on Sabadell United and Gibraltar loans, which are subject to change upon receipt of final fair value estimates during the respective measurement periods.

In addition to loans issued in the normal course of business, the Company considers overdrafts on customer deposit accounts to be loans and reclassifies these overdrafts as loans in its consolidated balance sheets. At March 31, 2018 and December 31, 2017, overdrafts of $7.3 million and $7.4 million, respectively, have been reclassified to loans.

Loans with carrying values of $6.8 billion and $6.6 billion were pledged as collateral for borrowings at March 31, 2018 and December 31, 2017, respectively.

Aging Analysis

The following tables provide an analysis of the aging of loans as of March 31, 2018 and December 31, 2017. Past due and non-accrual loan amounts exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans.

	March 31, 2018
	Accruing
(Dollars in thousands)	Current or Less Than 30 days Past Due		30-59 days		60-89 days		> 90 days		Total Past Due		Non-accrual		Acquired Impaired		Total
Real estate- construction	$	1,157,115	$	842	$	129	$	—	$	971	$	2,634	$	38,905	$	1,199,625
Real estate- owner-occupied	2,474,611		4,767		3,461		—		8,228		35,144		94,261		2,612,244
Real estate- non-owner-occupied	5,319,962		7,269		2,526		6,789		16,584		9,378		91,158		5,437,082
Commercial and industrial	5,212,390		7,755		3,406		273		11,434		66,637		35,221		5,325,682
Residential mortgage	3,783,309		25,640		2,655		1,226		29,521		19,932		138,305		3,971,067
Consumer - home equity	2,309,222		11,860		3,191		—		15,051		16,383		80,530		2,421,186
Consumer - indirect automobile	48,581		1,166		175		—		1,341		743		6		50,671
Consumer - credit card	92,497		173		88		—		261		503		—		93,261
Consumer - other	585,969		2,484		706		—		3,190		2,621		3,492		595,272
Total	$	20,983,656	$	61,956	$	16,337	$	8,288	$	86,581	$	153,975	$	481,878	$	21,706,090

	December 31, 2017
	Accruing
(Dollars in thousands)	Current or Less Than 30 days Past Due		30-59 days		60-89 days		> 90 days		Total Past Due		Non-accrual		Acquired Impaired		Total
Real estate- construction	$	1,197,766	$	269	$	—	$	458	$	727	$	2,635	$	39,268	$	1,240,396
Real estate- owner-occupied	2,398,487		1,631		659		74		2,364		24,457		104,577		2,529,885
Real estate- non-owner-occupied	5,066,084		2,086		6,405		887		9,378		6,811		85,676		5,167,949
Commercial and industrial	5,014,438		5,788		5,726		146		11,660		77,823		31,146		5,135,067
Residential mortgage	2,877,048		10,083		8,136		5,317		23,536		17,387		138,381		3,056,352
Consumer - home equity	2,186,554		11,675		2,947		18		14,640		12,365		78,716		2,292,275
Consumer - indirect automobile	59,830		1,796		177		—		1,973		884		6		62,693
Consumer - credit card	95,264		140		374		—		514		590		—		96,368
Consumer - other	487,150		3,350		475		—		3,825		2,436		3,785		497,196
Total	$	19,382,621	$	36,818	$	24,899	$	6,900	$	68,617	$	145,388	$	481,555	$	20,078,181

Acquired Loans

As discussed in Note 3, during the third quarter of 2017, the Company acquired loans with fair values of $4.0 billion from Sabadell United. Certain loans that were acquired in this transaction were covered by loss share agreements between the FDIC and Sabadell United, which were assumed in connection with the Company's acquisition of Sabadell United and afford IBERIABANK loss protection. Covered loans were $150.0 million and $158.6 million at March 31, 2018 and December 31, 2017, respectively. Certain acquired loans from Sabadell United were to customers with addresses outside of the United States. Foreign loans, denominated in U.S. dollars, totaled $336.1 million and $325.5 million at March 31, 2018 and December 31, 2017, respectively.

During the first quarter of 2018, the Company acquired loans with fair values of $1.5 billion from Gibraltar.

Of the total loans acquired from Gibraltar, $1.46 billion were determined to have no evidence of deteriorated credit quality and are accounted for under ASC Topics 310-10 and 310-20. The remaining $10.2 million were determined to exhibit deteriorated credit quality since origination under ASC 310-30. The tables below show the balances acquired during the first quarter of 2018 for these two subsections of the portfolio as of the acquisition date. These amounts are subject to change due to the finalization of purchase accounting adjustments.

(Dollars in thousands)	Acquired Non-Impaired Loans
Contractually required principal and interest at acquisition	$	1,695,918
Expected losses and foregone interest	(19,952		)
Cash flows expected to be collected at acquisition	1,675,966
Fair value of acquired loans at acquisition	$	1,455,085

(Dollars in thousands)	Acquired Impaired Loans
Contractually required principal and interest at acquisition	$	43,779
Non-accretable difference (expected losses and foregone interest)	(31,174		)
Cash flows expected to be collected at acquisition	12,605
Accretable yield	(2,371		)
Basis in acquired loans at acquisition	$	10,234

The following is a summary of changes in the accretable difference for all loans accounted for under ASC 310-30 during the three months ended March 31:

(Dollars in thousands)	2018			2017
Balance at beginning of period	$	152,623		$	175,054
Additions	2,371			—
Transfers from non-accretable difference to accretable yield	(279		)	2,071
Accretion	(13,154		)	(14,596		)
Changes in expected cash flows not affecting non-accretable differences (1)	9,687			1,060
Balance at end of period	$	151,248		$	163,589

⁽¹⁾  Includes changes in cash flows expected to be collected due to the impact of changes in actual or expected timing of liquidation events, modifications, changes in interest rates and changes in prepayment assumptions.

Troubled Debt Restructurings

Information about the Company’s troubled debt restructurings ("TDRs") at March 31, 2018 and 2017 is presented in the following tables. Modifications of loans that are accounted for within a pool under ASC Topic 310-30 are excluded as TDRs. Accordingly, such modifications do not result in the removal of those loans from the pool, even if the modification of those loans would otherwise be considered a TDR. As a result, all such acquired loans that would otherwise meet the criteria for classification as a TDR are excluded from the tables below.

TDRs totaling $27.2 million and $13.2 million occurred during the three months ended March 31, 2018 and March 31, 2017, respectively, through modification of the original loan terms.

The following table provides information on how the TDRs were modified during the periods indicated:

	Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Extended maturities	$	5,619	$	7,199
Maturity and interest rate adjustment	108		3,224
Movement to or extension of interest-rate only payments	48		1,290
Interest rate adjustment	105		—
Forbearance	12,886		1,220
Other concession(s) (1)	8,434		232
Total	$	27,200	$	13,165

⁽¹⁾  Other concessions may include covenant waivers, forgiveness of principal or interest associated with a customer bankruptcy, or a combination of any of the above concessions.

Of the $27.2 million of TDRs occurring during the three months ended March 31, 2018, $12.9 million are on accrual status and $14.3 million are on non-accrual status. Of the $13.2 million of TDRs occurring during the three months ended March 31, 2017, $11.8 million were on accrual status and $1.4 million were on non-accrual status. The following table presents the end of period balance for loans modified in a TDR during the periods indicated:

	Three Months Ended March 31,
	2018					2017
(In thousands, except number of loans)	Number of Loans	Pre-modification Outstanding Recorded Investment		Post-modification Outstanding Recorded Investment		Number of Loans	Pre-modification Outstanding Recorded Investment		Post-modification Outstanding Recorded Investment
Real estate- construction	1	$	1,950	$	1,049	—	$	—	$	—
Real estate- owner-occupied	2	10,691		9,324		3	3,004		2,999
Real estate- non-owner-occupied	9	1,089		1,091		7	1,867		1,855
Commercial and industrial	18	14,429		13,314		15	435		427
Residential mortgage	—	—		—		4	259		241
Consumer - home equity	14	1,809		1,795		37	6,622		6,607
Consumer - indirect	11	137		119		13	184		174
Consumer - other	10	511		508		22	867		862
Total	65	$	30,616	$	27,200	101	$	13,238	$	13,165

Information detailing TDRs that defaulted during the three-month periods ended March 31, 2018 and 2017, and were modified in the previous twelve months (i.e., the twelve months prior to the default) is presented in the following tables. The Company has defined a default as any loan with a payment that is currently past due greater than 30 days, or was past due greater than 30 days at any point during the respective periods, or since the date of modification, whichever is shorter.

	Three Months Ended March 31,
	2018			2017
(In thousands, except number of loans)	Number of Loans	Recorded Investment		Number of Loans	Recorded Investment
Real estate- construction	—	$	—	1	$	117
Real estate- owner-occupied	3	10,187		9	14,732
Real estate- non-owner-occupied	9	492		10	5,041
Commercial and industrial	29	9,708		21	4,186
Residential mortgage	6	598		22	1,793
Consumer - home equity	24	2,331		31	1,337
Consumer - indirect automobile	34	322		43	517
Consumer - other	17	1,035		25	693
Total	122	$	24,673	162	$	28,416

XML

Acquisition Activity

3 Months Ended

Mar. 31, 2018

Business Combinations [Abstract]

Acquisition Activity

ACQUISITION ACTIVITY

The acquisitions discussed below qualify as business combinations. The Company accounts for business combinations under the acquisition method in accordance with ASC Topic 805, Business Combinations. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017, for further discussion of the Company's accounting for business combinations.

2018 Acquisitions

Acquisition of Gibraltar

The Company completed the acquisition of Gibraltar Private Bank & Trust Co. ("Gibraltar") on March 23, 2018. The acquisition added $1.5 billion in loans and $1.1 billion in deposits, based on preliminary purchase accounting adjustments. Gibraltar operated eight offices in total, with seven located in the Florida metropolitan statistical areas of Miami, Key West, and Naples and one in New York City.

Under the terms of the Agreement and Plan of Merger, Gibraltar common shareholders received 1.9749 shares of IBERIABANK Corporation common stock for each outstanding share of Gibraltar common stock. Based on the Company's closing common stock price of $77.00 per share on March 23, 2018, the aggregate value of the acquisition consideration paid at the time of closing was approximately $214.7 million.

During the first quarter of 2018, the Company recorded preliminary purchase price allocations related to Gibraltar, which resulted in goodwill of $42.5 million. The following table summarizes the consideration paid for Gibraltar's net assets and the preliminary fair value estimates of the identifiable assets acquired and liabilities assumed as of the acquisition date.

(Dollars in thousands)	Number of Shares	Amount
Equity consideration
Common stock issued	2,787,773	$	214,659
Total equity consideration		214,659
Non-equity consideration
Cash		7
Total consideration paid		214,666
Fair value of net assets assumed including identifiable intangible assets		172,136
Goodwill		$	42,530

(Dollars in thousands)	Gibraltar Fair Value (Preliminary)
Assets
Cash and cash equivalents	$	102,570
Investment securities	19,169
Equity securities	27,519
Loans	1,465,319
Core deposit intangible assets	18,529
Deferred tax asset, net	689
Other assets	14,382
Total assets acquired	$	1,648,177
Liabilities
Deposit liabilities	$	1,064,803
Long-term borrowings	405,107
Other liabilities	6,131
Total liabilities assumed	$	1,476,041

The following is a description of the methods used to determine the fair values of significant assets acquired and liabilities assumed presented above.

Cash and Cash Equivalents: The carrying amount of these assets is a reasonable estimate of fair value based on the short-term nature of these assets.

Investment Securities: Fair values for securities were based on quoted market prices from multiple bond dealers. The simple average of the prices received was used to calculate the adjustments.

Equity Securities: The carrying amount of these securities is a reasonable estimate of fair value based on the short-term nature of these assets.

Loans: Fair values for loans were based on a discounted cash flow methodology that considered factors including loan type, classification status, remaining term of the loan, fixed or variable interest rate, amortization status and current discount rates. The discount rates used for loans were based on current market rates for new originations of comparable loans and included adjustments for any liquidity concerns. The discount rate did not include an explicit factor for credit losses, as that was included as a reduction to the estimated cash flows.

Core Deposit Intangible Assets ("CDI"): The fair value for CDI was estimated based on a discounted cash flow methodology that gave appropriate consideration to expected customer attrition rates, net maintenance cost of the deposit base, alternative costs of funds, and the interest costs associated with the customer deposits. The CDI is being amortized over its estimated useful life of approximately ten years utilizing an accelerated method.

Deposit Liabilities: The fair values used for the demand and savings deposits by definition equal the amount payable on demand at the acquisition date. Fair values for time deposits were estimated using a discounted cash flow analysis, that applied interest rates currently being offered to the contractual interest rates on such time deposits.

Long-term Borrowings: The carrying amount of long-term borrowings at the acquisition date approximated fair value, as the Company immediately paid off the debt upon acquisition.

Acquisition of SolomonParks

On January 12, 2018, the Company's subsidiary, Lenders Title Company ("LTC"), acquired SolomonParks Title & Escrow, LLC ("SolomonParks"). Under the terms of the Agreement, LTC paid $3.3 million in cash to acquire eight title offices in the Nashville, Tennessee area, which resulted in goodwill of $3.4 million. In addition, the agreement provides for potential additional cash consideration based on gross revenues over a two-year period after the acquisition. The following table summarizes the preliminary fair value estimates of the identifiable assets acquired and liabilities assumed as of the acquisition date.

(Dollars in thousands)	SolomonParks Fair Value (Preliminary)
Assets
Premise and equipment, net	$	42
Non-compete agreement	156
Title Plant investment	15
Total assets acquired	$	213
Liabilities
Contingent consideration	$	343
Total liabilities assumed	$	343

Information regarding the preliminary allocation of goodwill recorded as a result of these acquisitions to the Company's reportable segments is provided in Note 7 "Goodwill and Other Intangible Assets." The goodwill recorded as a result of these acquisitions is not deductible for tax purposes.

2017 Acquisition

Acquisition of Sabadell United

The Company completed the acquisition of Sabadell United Bank, N.A. ("Sabadell United") from Banco de Sabadell, S.A. on July 31, 2017. The acquisition of Sabadell United constituted a business combination. Accordingly, assets acquired, liabilities assumed, and consideration exchanged were recorded at their estimated fair value on the acquisition date. The acquisition added $4.0 billion in loans and $4.4 billion in deposits after fair value adjustments. The acquisition expanded our presence in Southeast Florida adding 25 offices serving the Miami metropolitan area and three offices in Naples, Sarasota and Tampa.

Under the terms of the Stock Purchase Agreement, Banco de Sabadell, S.A. received $809.2 million in cash and 2,610,304 shares of IBERIABANK Corporation common stock in exchange for 100 percent of Sabadell United's common stock. The cash consideration was financed through two public common stock offerings completed on December 7, 2016, and March 7, 2017.

During the third quarter of 2017, the Company recorded preliminary purchase price allocations related to Sabadell United. Throughout the remainder of 2017 and the first quarter of 2018, the Company continued to analyze the valuations assigned to the acquired assets and liabilities assumed. Based on new information relating to events or circumstances existing at the acquisition date and revised valuations, the Company updated estimated fair values increasing goodwill by $1.4 million to $463.4 million during the first quarter of 2018. This increase is primarily a result of a change in the estimated fair value of the deferred tax asset. Asof March 31, 2018, the Company continues to review its fair value estimates and additional adjustments may be required.The following table summarizes the consideration paid for Sabadell United's net assets and the preliminary fair value estimates of identifiable assets acquired and liabilities assumed as of the acquisition date.

(Dollars in thousands)	Number of Shares	Amount
Equity consideration
Common stock issued	2,610,304	$	211,043
Total equity consideration		211,043
Non-equity consideration
Cash		809,159
Total consideration paid		1,020,202
Fair value of net assets assumed including identifiable intangible assets		556,799
Goodwill		$	463,403

(Dollars in thousands)	Sabadell United Fair Value (Preliminary)
Assets
Cash and cash equivalents	$	318,834
Investment securities	964,123
Loans	4,025,946
Core deposit intangible assets	66,600
Deferred tax asset, net	33,469
Other assets	89,745
Total assets acquired	$	5,498,717
Liabilities
Deposit liabilities	$	4,382,780
Short-term borrowings	520,539
Other liabilities	38,599
Total liabilities assumed	$	4,941,918

Information regarding the preliminary allocation of goodwill recorded as a result of the acquisition to the Company's reportable segments is provided in Note 7 "Goodwill and Other Intangible Assets." The goodwill recorded as a result of the acquisition is not deductible for tax purposes.

All measurement period adjustments made during the first three months of 2018 have been deemed insignificant individually and in the aggregate. The Company will finalize its valuation of the Sabadell United acquisition within the measurement period (i.e., no later than July 31, 2018). See Note 3, Acquisition Activity, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017, for a description of the methods used to determine the fair values of significant assets acquired and liabilities assumed presented above.

The Company's consolidated financial statements as of and for the period ended March 31, 2018 include the operating results of the acquired assets and liabilities assumed. Due to the system conversion of Sabadell United in October 2017 and subsequent streamlining and integration of the operating activities into those of the Company, historical reporting for the former Sabadell United operations is impracticable and thus disclosure of the revenue from the assets acquired and income before income taxes is impracticable for the period subsequent to acquisition.

The following table presents unaudited pro forma information as if the acquisition occurred on January 1, 2016 under the "Unaudited Pro Forma" column. The pro forma information does not necessarily reflect the results of operations that would have occurred had the Company acquired Sabadell United on January 1, 2016. Furthermore, cost savings and other business synergies related to the acquisition are not reflected in the pro forma amounts.

	Unaudited Pro Forma for
(Dollars in thousands)	Three months ended March 31, 2017
Net interest income	$	231,087
Non-interest income	54,755
Net income	43,562

This pro forma information combines the historical consolidated results of operations of IBERIABANK and Sabadell United for the periods presented and gives effect to the following non recurring adjustments:

Fair value adjustments: Pro forma adjustment to net interest income of $5.1 million for the three months ended March 31, 2017 to record estimated amortization of premiums and accretion of discounts on acquired loans, securities, and deposits.

Sabadell United accretion / amortization: Pro forma adjustment to net interest income of $318.5 thousand for the three months ended March 31, 2017 to eliminate Sabadell United's amortization of premiums and accretion of discounts on previously acquired loans, securities, FDIC indemnification asset, and deposits.

Sabadell United provision for loan losses: Pro forma adjustments were made to provision for loan losses of $1.6 million for the three months ended March 31, 2017 to eliminate the reversal (benefit) of Sabadell United's release of provision for loan losses and to account for the provision for loan losses on new loans originated during the period presented.

Amortization of acquired intangibles: Pro forma adjustment to non-interest expense of $1.5 million for the three months ended March 31, 2017 to record estimated amortization of acquired intangible assets.

Other adjustments: Pro forma results also include adjustments related to the removal of benefit from release of reserve for unfunded lending commitments, removal of FDIC clawback liability expense, adjustments to FDIC insurance and other regulatory assessment expenses and related income tax effects.

XML

Investment Securities

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Investment Securities

INVESTMENT SECURITIES

The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following:

	March 31, 2018
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	6,824	$	—	$	—		$	6,824
U.S. Government-sponsored enterprise obligations	41,001		11		(654		)	40,358
Obligations of state and political subdivisions	267,962		1,228		(4,156		)	265,034
Mortgage-backed securities	4,277,033		279		(121,215		)	4,156,097
Other securities	75,205		106		(1,138		)	74,173
Total securities available for sale	$	4,668,025	$	1,624	$	(127,163	)	$	4,542,486
Securities held to maturity:
Obligations of state and political subdivisions	$	204,404	$	726	$	(4,120	)	$	201,010
Mortgage-backed securities	19,837		35		(1,014		)	18,858
Total securities held to maturity	$	224,241	$	761	$	(5,134	)	$	219,868

	December 31, 2017
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	41,003	$	18	$	(406	)	$	40,615
Obligations of state and political subdivisions	271,451		4,246		(1,493		)	274,204
Mortgage-backed securities	4,221,472		1,461		(61,028		)	4,161,905
Other securities	114,005		247		(914		)	113,338
Total securities available for sale	$	4,647,931	$	5,972	$	(63,841	)	$	4,590,062
Securities held to maturity:
Obligations of state and political subdivisions	$	206,736	$	1,530	$	(275	)	$	207,991
Mortgage-backed securities	20,582		41		(650		)	19,973
Total securities held to maturity	$	227,318	$	1,571	$	(925	)	$	227,964

Securities with carrying values of $2.1 billion were pledged to secure public deposits and other borrowings at both March 31, 2018 and December 31, 2017.

Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, is as follows:

	March 31, 2018
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	—		$	693	$	—		$	—	$	—		$	693
U.S. Government-sponsored enterprise obligations	(419		)	29,580		(235		)	9,765		(654		)	39,345
Obligations of state and political subdivisions	(1,147		)	96,138		(3,009		)	66,404		(4,156		)	162,542
Mortgage-backed securities	(68,161		)	2,847,244		(53,054		)	1,191,233		(121,215		)	4,038,477
Other securities	(1,138		)	60,304		—			—		(1,138		)	60,304
Total securities available for sale	$	(70,865	)	$	3,033,959	$	(56,298	)	$	1,267,402	$	(127,163	)	$	4,301,361
Securities held to maturity:
Obligations of state and political subdivisions	$	(4,066	)	$	150,188	$	(54	)	$	2,976	$	(4,120	)	$	153,164
Mortgage-backed securities	(11		)	323		(1,003		)	18,187		(1,014		)	18,510
Total securities held to maturity	$	(4,077	)	$	150,511	$	(1,057	)	$	21,163	$	(5,134	)	$	171,674

	December 31, 2017
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	(254	)	$	29,744	$	(152	)	$	9,848	$	(406	)	$	39,592
Obligations of state and political subdivisions	(326		)	31,601		(1,167		)	68,609		(1,493		)	100,210
Mortgage-backed securities	(26,263		)	2,677,338		(34,765		)	1,226,058		(61,028		)	3,903,396
Other securities	(914		)	75,302		—			—		(914		)	75,302
Total securities available for sale	$	(27,757	)	$	2,813,985	$	(36,084	)	$	1,304,515	$	(63,841	)	$	4,118,500
Securities held to maturity:
Obligations of state and political subdivisions	$	(263	)	$	65,817	$	(12	)	$	3,031	$	(275	)	$	68,848
Mortgage-backed securities	(2		)	333		(648		)	19,269		(650		)	19,602
Total securities held to maturity	$	(265	)	$	66,150	$	(660	)	$	22,300	$	(925	)	$	88,450

The Company assessed the nature of the unrealized losses in its portfolio as of March 31, 2018 and December 31, 2017 to determine if there are losses that should be deemed other-than-temporary. In its analysis of these securities, management considered numerous factors to determine whether there were instances where the amortized cost basis of the debt securities would not be fully recoverable, including, but not limited to:

• The length of time and extent to which the estimated fair value of the securities was less than their amortized cost;

• Whether adverse conditions were present in the operations, geographic area, or industry of the issuer;

• The payment structure of the security, including scheduled interest and principal payments, including the issuer’s failures to make scheduled payments, if any, and the likelihood of failure to make scheduled payments in the future;

• Changes to the rating of the security by a rating agency; and

• Subsequent recoveries or additional declines in fair value after the balance sheet date.

Management believes it has considered these factors, as well as all relevant information available, when determining the expected future cash flows of the securities in question. In each instance, management has determined the cost basis of the securities would be fully recoverable. Management also has the intent to hold debt securities until their maturity or anticipated recovery if the security is classified as available for sale. In addition, management does not believe the Company will be required to sell debt securities before the anticipated recovery of the amortized cost basis of the security. As a result of the Company's analysis, no declines in the estimated fair value of the Company's investment securities were deemed to be other-than-temporary at March 31, 2018 or December 31, 2017.

At March 31, 2018, 635 debt securities had unrealized losses of 2.87% of the securities’ amortized cost basis. At December 31, 2017, 544 debt securities had unrealized losses of 1.52% of the securities’ amortized cost basis. The unrealized losses for each of the securities related to market interest rate changes and not credit concerns of the issuers. Additional information on securities that have been in a continuous loss position for over twelve months at March 31, 2018 and December 31, 2017 is presented in the following table.

(Dollars in thousands)	March 31, 2018		December 31, 2017
Number of securities:
Mortgage-backed securities	184		181
Obligations of state and political subdivisions	28		28
Other	1		1
	213		210
Amortized Cost Basis:
Mortgage-backed securities	$	1,263,477	$	1,280,739
Obligations of state and political subdivisions	72,443		72,820
Other	10,000		10,000
	$	1,345,920	$	1,363,559
Unrealized Loss:
Mortgage-backed securities	$	54,057	$	35,412
Obligations of state and political subdivisions	3,063		1,180
Other	235		152
	$	57,355	$	36,744

The securities noted above carry a rating of AA+/Aaa by S&P and Moody's.

The amortized cost and estimated fair value of investment securities by maturity at March 31, 2018 are presented in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Weighted average yields are calculated on the basis of the yield to maturity based on the amortized cost of each security.

	Securities Available for Sale						Securities Held to Maturity
(Dollars in thousands)	Weighted Average Yield		Amortized Cost		Estimated Fair Value		Weighted Average Yield		Amortized Cost		Estimated Fair Value
Within one year or less	2.06	%	$	6,667	$	6,670	3.04	%	$	1,445	$	1,448
One through five years	2.04		134,449		132,594		2.98		8,369		8,370
After five through ten years	2.36		887,796		868,090		2.66		45,690		45,450
Over ten years	2.38		3,639,113		3,535,132		2.56		168,737		164,600
	2.38	%	$	4,668,025	$	4,542,486	2.60	%	$	224,241	$	219,868

The following is a summary of realized gains and losses from the sale of securities classified as available for sale. Gains or losses on securities sold are recorded on the trade date, using the specific identification method.

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Realized gains	$	9		$	—
Realized losses	(68		)	—
	$	(59	)	$	—

In addition to the gains above, the Company realized certain gains on calls of securities held to maturity that were not significant to the consolidated financial statements.

Other Equity Securities

The Company accounts for the following securities at cost less impairment plus or minus any observable price changes, which approximates fair value, with the exception of CRA and Community Development Investment Funds, which are recorded at fair value. Other Equity Securities, which are presented in “other assets” on the consolidated balance sheets, are as follows:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Federal Home Loan Bank (FHLB) stock	$	90,561	$	95,171
Federal Reserve Bank (FRB) stock	79,191		79,191
CRA and Community Development Investment Funds	9,801		—
Other investments	9,705		3,008
	$	189,258	$	177,370

XML

Allowance for Credit Losses and Credit Quality

3 Months Ended

Mar. 31, 2018

Receivables [Abstract]

Allowance for Credit Losses and Credit Quality

ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY

Allowance for Credit Losses Activity

A summary of changes in the allowance for credit losses for the three months ended March 31 is as follows:

(Dollars in thousands)	2018			2017
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	$	140,891		$	144,719
Provision for loan and lease losses	7,986			6,154
Transfer of balance to OREO and other	(47		)	73
Charge-offs	(9,116		)	(7,291		)
Recoveries	4,813			1,235
Allowance for loan and lease losses at end of period	$	144,527		$	144,890
Reserve for unfunded commitments at beginning of period	$	13,208		$	11,241
Provision for unfunded lending commitments	224			419
Reserve for unfunded commitments at end of period	$	13,432		$	11,660
Allowance for credit losses at end of period	$	157,959		$	156,550

A summary of changes in the allowance for credit losses, by loan portfolio type, for the three months ended March 31 is as follows:

	2018
(Dollars in thousands)	Commercial Real Estate			Commercial and Industrial			Residential Mortgage			Consumer			Total
Allowance for loan and lease losses at beginning of period	$	54,201		$	53,916		$	9,117		$	23,657		$	140,891
Provision for (Reversal of) loan and lease losses	6,377			294			(686		)	2,001			7,986
Transfer of balance to OREO and other	(47		)	—			—			—			(47		)
Charge-offs	(114		)	(5,378		)	(105		)	(3,519		)	(9,116		)
Recoveries	191			3,698			22			902			4,813
Allowance for loan and lease losses at end of period	$	60,608		$	52,530		$	8,348		$	23,041		$	144,527
Reserve for unfunded commitments at beginning of period	$	4,531		$	5,309		$	555		$	2,813		$	13,208
Provision for (Reversal of) unfunded commitments	1,476			(1,004		)	(15		)	(233		)	224
Reserve for unfunded commitments at end of period	$	6,007		$	4,305		$	540		$	2,580		$	13,432
Allowance on loans individually evaluated for impairment	$	2,506		$	14,040		$	178		$	2,974		$	19,698
Allowance on loans collectively evaluated for impairment	35,871			36,208			2,073			16,544			90,696
Allowance on loans acquired with deteriorated credit quality	22,231			2,282			6,097			3,523			34,133
Loans and leases, net of unearned income:
Balance at end of period	$	9,248,951		$	5,325,682		$	3,971,067		$	3,160,390		$	21,706,090
Balance at end of period individually evaluated for impairment	78,489			78,725			6,041			33,277			196,532
Balance at end of period collectively evaluated for impairment	8,946,138			5,211,736			3,826,721			3,043,085			21,027,680
Balance at end of period acquired with deteriorated credit quality	224,324			35,221			138,305			84,028			481,878

	2017
(Dollars in thousands)	Commercial Real Estate			Commercial and Industrial			Residential Mortgage			Consumer			Total
Allowance for loan losses at beginning of period	$	49,231		$	60,939		$	11,249		$	23,300		$	144,719
Provision for (Reversal of) loan and lease losses	1,786			2,557			(1,060		)	2,871			6,154
Transfer of balance to OREO and other	377			(350		)	2			44			73
Charge-offs	(95		)	(3,762		)	(22		)	(3,412		)	(7,291		)
Recoveries	196			84			43			912			1,235
Allowance for loan losses at end of period	$	51,495		$	59,468		$	10,212		$	23,715		$	144,890
Reserve for unfunded commitments at beginning of period	$	3,207		$	4,537		$	657		$	2,840		$	11,241
Provision for (Reversal of) unfunded commitments	1,379			(885		)	(49		)	(26		)	419
Reserve for unfunded commitments at end of period	$	4,586		$	3,652		$	608		$	2,814		$	11,660
Allowance on loans individually evaluated for impairment	$	1,916		$	25,056		$	113		$	1,724		$	28,809
Allowance on loans collectively evaluated for impairment	26,872			32,383			3,907			17,764			80,926
Allowance on loans acquired with deteriorated credit quality	22,707			2,029			6,192			4,227			35,155
Loans, net of unearned income:
Balance at end of period	$	7,021,341		$	3,975,734		$	1,296,358		$	2,838,769		$	15,132,202
Balance at end of period individually evaluated for impairment	74,351			164,405			5,048			25,308			269,112
Balance at end of period collectively evaluated for impairment	6,687,651			3,778,775			1,176,017			2,723,308			14,365,751
Balance at end of period acquired with deteriorated credit quality	259,339			32,554			115,293			90,153			497,339

Portfolio Segment Risk Factors

Commercial real estate loans include loans to commercial customers for long-term financing of land and buildings or for land development or construction of a building. These loans are repaid through revenues from operations of the businesses, rents of properties, sales of properties and refinances. Commercial and industrial loans and leases represent loans to commercial customers to finance general working capital needs, equipment purchases and leases and other projects where repayment is derived from cash flows resulting from business operations. The Company originates commercial business loans on a secured and, to a lesser extent, unsecured basis.

Residential mortgage loans consist of loans to consumers to finance a primary residence. The vast majority of the residential mortgage loan portfolio is comprised of non-conforming 1-4 family mortgage loans secured by properties located in the Company's market areas and originated under terms and documentation that permit their sale in a secondary market.

Consumer loans are offered by the Company in order to provide a full range of retail financial services to its customers and include home equity, credit card and other direct consumer installment loans. The Company originates substantially all of its consumer loans in its primary market areas. Loans in the consumer segment are sensitive to unemployment and other key consumer economic measures.

Credit Quality

The Company utilizes an asset risk classification system in accordance with guidelines established by the Federal Reserve Board as part of its efforts to monitor commercial asset quality. “Special mention” loans are defined as loans with potential weaknesses that may, if not corrected, result in future deterioration of the loan. Special mention loans do not expose the Company to sufficient risk to warrant adverse classification. For problem assets with identified credit issues, the Company has two primary classifications: “substandard” and “doubtful.”

Substandard assets have one or more defined weaknesses and are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Doubtful assets have the weaknesses of substandard assets with the additional characteristic that the weaknesses make collection or liquidation in full satisfaction of the loan balance outstanding questionable, which makes probability of loss higher based on currently existing facts, conditions, and values. Loans classified as “Pass” do not meet the criteria set forth for special mention, substandard, or doubtful classification and are not considered criticized. Asset risk classifications are determined at origination or acquisition and reviewed on an ongoing basis. Risk classifications are changed if, in the opinion of management, the risk profile of the customer has changed since the last review of the loan relationship.

The Company’s investment in loans by credit quality indicator is presented in the following tables. Asset risk classifications for commercial loans and leases reflect the classification as of March 31, 2018 and December 31, 2017. Credit quality information in the tables below includes total loans acquired (including acquired impaired loans) at the net loan balance, after the application of premiums/discounts, at March 31, 2018 and December 31, 2017. Loan premiums/discounts represent the adjustment of acquired loans to fair value at the acquisition date, as adjusted for income accretion and changes in cash flow estimates in subsequent periods. Loan premiums/discounts include preliminary discounts recorded on acquired Sabadell United and Gibraltar loans, which are subject to change upon receipt of final fair value estimates during the measurement period.

Loan delinquency is the primary credit quality indicator that the Company utilizes to monitor consumer asset quality.

	March 31, 2018										December 31, 2017
(Dollars in thousands)	Pass		Special Mention		Sub- standard		Doubtful		Total		Pass		Special Mention		Sub- standard		Doubtful		Loss		Total
Commercial real estate - construction	$	1,153,604	$	16,399	$	29,610	$	12	$	1,199,625	$	1,189,490	$	20,351	$	30,541	$	14	$	—	$	1,240,396
Commercial real estate - owner-occupied	2,464,072		83,356		56,409		8,407		2,612,244		2,388,715		82,114		56,590		2,466		—		2,529,885
Commercial real estate- non-owner-occupied	5,335,816		45,905		51,089		4,272		5,437,082		5,104,074		19,311		42,702		1,744		118		5,167,949
Commercial and industrial	5,124,676		55,041		107,126		38,839		5,325,682		4,882,554		88,149		128,961		35,403		—		5,135,067
Total	$	14,078,168	$	200,701	$	244,234	$	51,530	$	14,574,633	$	13,564,833	$	209,925	$	258,794	$	39,627	$	118	$	14,073,297

	March 31, 2018						December 31, 2017
(Dollars in thousands)	Current		30+ Days Past Due		Total		Current		30+ Days Past Due		Total
Residential mortgage	$	3,859,751	$	111,316	$	3,971,067	$	2,962,043	$	94,309	$	3,056,352
Consumer - home equity	2,376,171		45,015		2,421,186		2,250,205		42,070		2,292,275
Consumer - indirect automobile	48,587		2,084		50,671		59,836		2,857		62,693
Consumer - credit card	92,497		764		93,261		95,263		1,105		96,368
Consumer - other	589,098		6,174		595,272		490,399		6,797		497,196
Total	$	6,966,104	$	165,353	$	7,131,457	$	5,857,746	$	147,138	$	6,004,884

Impaired Loans

Information on the Company’s investment in impaired loans, which include all TDRs and all other non-accrual loans evaluated or measured individually for impairment for purposes of determining the ALLL, is presented in the following tables as of and for the periods indicated.

	March 31, 2018							December 31, 2017
	Unpaid Principal Balance		Recorded Investment		Related Allowance			Unpaid Principal Balance		Recorded Investment		Related Allowance
(Dollars in thousands)
With no related allowance recorded:
Commercial real estate- construction	$	11,153	$	11,153	$	—		$	13,763	$	13,013	$	—
Commercial real estate- owner-occupied	43,562		36,042		—			50,867		44,482		—
Commercial real estate- non-owner-occupied	10,575		10,449		—			15,370		14,975		—
Commercial and industrial	45,720		36,829		—			103,013		70,254		—
Residential mortgage	1,083		1,083		—			2,004		2,001		—
Consumer - home equity	31		31		—			5,906		5,634		—
Consumer -other	—		—		—			75		75		—
With an allowance recorded:
Commercial real estate- construction	236		154		(18		)	238		156		(19		)
Commercial real estate- owner-occupied	17,536		17,419		(1,860		)	13,314		13,287		(949		)
Commercial real estate- non-owner-occupied	3,399		3,272		(628		)	6,051		5,872		(620		)
Commercial and industrial	46,705		41,896		(14,040		)	35,306		32,162		(12,736		)
Residential mortgage	5,357		4,958		(178		)	5,179		4,748		(172		)
Consumer - home equity	28,917		28,187		(2,435		)	27,189		26,575		(2,358		)
Consumer - indirect automobile	1,004		656		(75		)	1,034		679		(79		)
Consumer - other	4,493		4,403		(464		)	4,320		4,214		(419		)
Total	$	219,771	$	196,532	$	(19,698	)	$	283,629	$	238,127	$	(17,352	)
Total commercial loans and leases	$	178,886	$	157,214	$	(16,546	)	$	237,922	$	194,201	$	(14,324	)
Total mortgage loans	6,440		6,041		(178		)	7,183		6,749		(172		)
Total consumer loans	34,445		33,277		(2,974		)	38,524		37,177		(2,856		)

	Three Months Ended March 31, 2018				Three Months Ended March 31, 2017
	Average Recorded Investment		Interest Income Recognized		Average Recorded Investment		Interest Income Recognized
(Dollars in thousands)
With no related allowance recorded:
Commercial real estate- construction	$	10,470	$	144	$	—	$	—
Commercial real estate- owner-occupied	36,277		334		37,197		339
Commercial real estate- non-owner-occupied	10,557		98		5,988		17
Commercial and industrial	27,832		385		90,664		448
Residential mortgage	1,090		12		735		5
Consumer - home equity	32		—		4,158		40
With an allowance recorded:
Commercial real estate- construction	153		1		1,984		1
Commercial real estate- owner-occupied	17,608		112		20,980		79
Commercial real estate- non-owner-occupied	3,302		10		8,587		94
Commercial and industrial	44,056		196		78,695		220
Residential mortgage	4,974		44		4,335		42
Consumer - home equity	28,203		292		16,713		179
Consumer - indirect automobile	717		5		767		7
Consumer - other	4,483		62		3,328		52
Total	$	189,754	$	1,695	$	274,131	$	1,523
Total commercial loans and leases	$	150,255	$	1,280	$	244,095	$	1,198
Total mortgage loans	6,064		56		5,070		47
Total consumer loans	33,435		359		24,966		278

As of March 31, 2018 and December 31, 2017, the Company was not committed to lend a material amount of additional funds to any customer whose loan was classified as impaired or as a troubled debt restructuring.

XML

Goodwill and Other Intangible Assets

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Other Intangible Assets

GOODWILL AND OTHER INTANGIBLE ASSETS

Goodwill

Changes to the carrying amount of goodwill by reporting unit for the three months ended March 31, 2018, and the year ended December 31, 2017 are provided in the following table.

(Dollars in thousands)	IBERIABANK		Mortgage		LTC		Total
Balance, December 31, 2016	$	698,513	$	23,178	$	5,165	$	726,856
Goodwill acquired during the year (preliminary allocation)	462,046		—		—		462,046
Balance, December 31, 2017	$	1,160,559	$	23,178	$	5,165	$	1,188,902
Goodwill acquired during the year (preliminary allocation) and adjustments	43,887		—		3,380		47,267
Balance, March 31, 2018	$	1,204,446	$	23,178	$	8,545	$	1,236,169

On March 23, 2018 the Company completed its acquisition of Gibraltar. In connection with the acquisition, the Company recorded $42.5 million of goodwill based on preliminary adjustments. On January 12, 2018, the Company's subsidiary, LTC, completed its acquisition of SolomonParks. In connection with the acquisition, LTC recorded $3.4 million of goodwill based on preliminary adjustments. In addition, goodwill adjustments were made during the first three months of 2018 as a result of measurement period updates to the preliminary fair value estimates related to the 2017 acquisition of Sabadell United. See Note 3 for additional information regarding these acquisitions.

The Company performed the required annual goodwill impairment test as of October 1, 2017. The Company’s annual impairment test did not indicate impairment in any of the Company’s reporting units as of the testing date. Following the testing date, management evaluated the events and changes that could indicate that goodwill might be impaired and concluded that a subsequent interim test was not necessary.

Mortgage Servicing Rights

Mortgage servicing rights are recorded at the lower of cost or market value in “other intangible assets” on the Company's consolidated balance sheets and amortized over the remaining servicing life of the loans, with consideration given to prepayment assumptions. Mortgage servicing rights had the following carrying values as of the periods indicated:

	March 31, 2018							December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
(Dollars in thousands)
Mortgage servicing rights	$	10,030	$	(4,128	)	$	5,902	$	9,588	$	(3,931	)	$	5,657

In addition, there was an insignificant amount of non-mortgage servicing rights related to SBA loans as of March 31, 2018 and December 31, 2017, respectively.

Title Plant

The Company held title plant assets recorded in “other intangible assets” on the Company's consolidated balance sheets totaling $6.8 million on March 31, 2018 and $6.7 million on December 31, 2017. The increase in title plant assets was the result of the SolomonParks acquisition during the first quarter of 2018. No events or changes in circumstances occurred during the three months ended March 31, 2018 to suggest the carrying value of the title plant was not recoverable.

Intangible assets subject to amortization

In connection with the acquisition of Gibraltar, the Company recorded $18.5 million of core deposit intangible assets. Core deposit intangible assets are subject to amortization over a ten year period. In connection with the acquisition of SolomonParks, the Company recorded $155.9 thousand of non-compete agreement intangible assets. Non-compete agreement intangible assets are subject to amortization over a five year period. Definite-lived intangible assets had the following carrying values included in “other intangible assets” on the Company’s consolidated balance sheets as of the periods indicated:

	March 31, 2018							December 31, 2017
(Dollars in thousands)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Core deposit intangible assets	$	136,183	$	(46,736	)	$	89,447	$	127,957	$	(51,971	)	$	75,986
Customer relationship intangible asset	1,385		(1,262		)	123		1,143		(996		)	147
Non-compete agreement	206		(36		)	170		63		(39		)	24
Total	$	137,774	$	(48,034	)	$	89,740	$	129,163	$	(53,006	)	$	76,157

XML

Derivative Instruments and Other Hedging Activities

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments and Other Hedging Activities

DERIVATIVE INSTRUMENTS AND OTHER HEDGING ACTIVITIES

The Company enters into derivative financial instruments to manage interest rate risk, exposures related to liquidity and credit risk, and to facilitate customer transactions. The primary types of derivatives used by the Company include interest rate swap agreements, foreign exchange contracts, interest rate lock commitments, forward sales commitments, written and purchased options and credit derivatives. All derivative instruments are recognized on the consolidated balance sheets as "other assets" or "other liabilities" at fair value, as required by ASC Topic 815, Derivatives and Hedging.

For cash flow hedges, the effective and ineffective portions of the gain or loss related to the derivative instrument is initially reported as a component of other comprehensive income and subsequently reclassified into earnings when the forecasted transaction affects earnings or when the hedge is terminated, per the Company’s early adoption of ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities, as of January 1, 2018. In applying hedge accounting for derivatives, the Company establishes and documents a method for assessing the effectiveness of the hedging derivative and a measurement approach for determining the ineffective aspect of the hedge upon the inception of the hedge. The Company has designated interest rate swaps in a cash flow hedge to convert forecasted variable interest payments to a fixed rate on its junior subordinated debt and has concluded that the forecasted transactions are probable of occurring.

For derivative instruments that are not designated as hedging instruments, changes in the fair value of the derivatives are recognized in earnings immediately.

Information pertaining to outstanding derivative instruments is as follows:

	Balance Sheet Location	Derivative Assets - Fair Value				Balance Sheet Location	Derivative Liabilities - Fair Value
(Dollars in thousands)		March 31, 2018		December 31, 2017			March 31, 2018		December 31, 2017
Derivatives designated as hedging instruments under ASC Topic 815:
Interest rate contracts	Other assets	$	—	$	—	Other liabilities	$	—	$	—
Total derivatives designated as hedging instruments under ASC Topic 815		$	—	$	—		$	—	$	—
Derivatives not designated as hedging instruments under ASC Topic 815:
Interest rate contracts	Other assets	$	5,827	$	20,446	Other liabilities	$	25,771	$	16,191
Foreign exchange contracts	Other assets	2		7		Other liabilities	2		7
Forward sales contracts	Other assets	2,851		136		Other liabilities	703		279
Written and purchased options	Other assets	8,383		10,654		Other liabilities	5,667		8,656
Other contracts	Other assets	9		22		Other liabilities	11		21
Total derivatives not designated as hedging instruments under ASC Topic 815		$	17,072	$	31,265		$	32,154	$	25,154
Total		$	17,072	$	31,265		$	32,154	$	25,154

	Derivative Assets - Notional Amount				Derivative Liabilities - Notional Amount
(Dollars in thousands)	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
Derivatives designated as hedging instruments under ASC Topic 815:
Interest rate contracts	$	108,500	$	—	$	—	$	108,500
Total derivatives designated as hedging instruments under ASC Topic 815	$	108,500	$	—	$	—	$	108,500
Derivatives not designated as hedging instruments under ASC Topic 815:
Interest rate contracts	$	1,356,990	$	1,218,464	$	1,276,990	$	1,218,464
Foreign exchange contracts	628		268		628		268
Forward sales contracts	96,810		82,347		215,918		142,578
Written and purchased options	339,852		278,638		164,341		165,198
Other contracts	29,676		29,755		71,889		86,744
Total derivatives not designated as hedging instruments under ASC Topic 815	$	1,823,956	$	1,609,472	$	1,729,766	$	1,613,252
Total	$	1,932,456	$	1,609,472	$	1,729,766	$	1,721,752

The Company has entered into risk participation agreements with counterparties to transfer or assume credit exposures related to interest rate derivatives. The notional amounts of risk participation agreements sold were $71.9 million and $86.7 million at March 31, 2018 and December 31, 2017, respectively. Assuming all underlying third party customers referenced in the swap contracts defaulted at March 31, 2018 and December 31, 2017, the exposure from these agreements would not be material based on the fair value of the underlying swaps.

The Company is party to collateral agreements with certain derivative counterparties. Such agreements require that the Company maintain collateral based on the fair values of individual derivative transactions. In the event of default by the Company, the counterparty would be entitled to the collateral.

At March 31, 2018, the Company was not required to post collateral due to the Company's derivative position at the balance sheet date. At December 31, 2017, the Company was required to post $552 thousand in cash or securities as collateral for its derivative transactions, which is included in "interest-bearing deposits in banks" on the Company’s consolidated balance sheets. Effective January 3, 2017, the Chicago Mercantile Exchange and LCH.Clearnet Limited amended their rulebooks to legally characterize variation margin payments for over-the-counter derivatives they clear as settlements of the derivatives' exposure rather than collateral against the exposures. In light of changes to the aforementioned rulebooks, the Board of Governors of the Federal Reserve System, the Office of the Comptroller of the Currency (OCC) and the FDIC issued guidance effective August 14, 2017, which is consistent with the SEC's accounting guidance, that allows institutions to treat centrally-cleared derivatives as settled for purposes of the capital rule. At March 31, 2018 and December 31, 2017, the Company was required to post $28.8 million and $5.1 million, respectively, in variation margin payments for its derivative transactions, which is now required to be netted against the fair value of the derivatives in "other assets/other liabilities" on the consolidated balance sheets. The Company does not anticipate additional assets will be required to be posted as collateral, nor does it believe additional assets would be required to settle its derivative instruments immediately if contingent features were triggered at March 31, 2018. The Company’s master netting agreements represent written, legally enforceable bilateral agreements that (1) create a single legal obligation for all individual transactions covered by the master agreement and (2) in the event of default, provide the non-defaulting counterparty the right to accelerate, terminate, and close-out on a net basis all transactions under the agreement and to promptly liquidate or set-off collateral posted by the defaulting counterparty. As permitted by U.S. GAAP, the Company does not offset fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral against recognized fair value amounts of derivatives executed with the same counterparty under a master netting agreement.

The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset.

	March 31, 2018
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet					Net
(Dollars in thousands)			Derivatives			Collateral  (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	5,827	$	(548	)	$	—	$	5,279
Written and purchased options	5,656		—			—		5,656
Total derivative assets subject to master netting arrangements	$	11,483	$	(548	)	$	—	$	10,935
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—	$	—
Interest rate contracts not designated as hedging instruments	25,771		(548		)	—		25,223
Written and purchased options	5,587		—			—		5,587
Total derivative liabilities subject to master netting arrangements	$	31,358	$	(548	)	$	—	$	30,810

^{(1) Consists of cash collateral recorded at cost, which approximates fair value, and investment securities.} 

	December 31, 2017
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet						Net
(Dollars in thousands)			Derivatives			Collateral (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	20,446	$	(12,469	)	$	—		$	7,977
Written and purchased options	8,610		—			—			8,610
Total derivative assets subject to master netting arrangements	$	29,056	$	(12,469	)	$	—		$	16,587
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—		$	—
Interest rate contracts not designated as hedging instruments	16,191		(12,469		)	(552		)	3,170
Total derivative liabilities subject to master netting arrangements	$	16,191	$	(12,469	)	$	(552	)	$	3,170

^{(1) Consists of cash collateral recorded at cost, which approximates fair value, and investment securities.} 

During the three months ended March 31, 2018 and 2017, the Company has not reclassified into earnings any gain or loss as a result of the discontinuance of cash flow hedges, because it was probable the original forecasted transaction would not occur by the end of the originally specified term.

At March 31, 2018, the Company does not expect to reclassify a material amount from accumulated other comprehensive income into interest income over the next twelve months for derivatives that will be settled.

At March 31, 2018 and 2017, and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements is as follows:

													Location of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	Amount of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)
			Amount of Gain (Loss) Recognized in OCI, net of taxes			Location of Gain (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain (Loss) Reclassified from Accumulated OCI into Income, net of taxes
(Dollars in thousands)
			For the Three Months Ended March 31
Derivatives in ASC Topic 815 Cash Flow Hedging Relationships		2018		2017			2018			2017				2018		2017
	Interest rate contracts	$	2,549	$	73	Interest expense	$	(116	)	$	(45	)	Interest expense	$	—	$	—
Total		$	2,549	$	73		$	(116	)	$	(45	)		$	—	$	—

Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, is as follows:

	Location of Gain (Loss) Recognized in  Income on Derivatives	Amount of Gain (Loss) Recognized in Income on Derivatives
		For the Three Months Ended March 31
(Dollars in thousands)		2018			2017
Interest rate contracts (1)	Other income	$	1,049		$	1,117
Foreign exchange contracts	Other income	5			7
Forward sales contracts	Mortgage income	3,387			(360		)
Written and purchased options	Mortgage income	648			655
Other contracts	Other income	(3		)	4
Total		$	5,086		$	1,423

^{(1) Includes fees associated with customer interest rate contracts.}

XML

Income Taxes (Notes)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Income Tax Disclosure [Text Block]

INCOME TAXES

The Company's provision for income taxes for the three months ended March 31, 2018 and 2017 is based on the estimated annual effective tax rate, plus discrete items.

The following table presents the provision for income taxes and the effective tax rates for the three months ended March 31, 2018 and 2017:

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Income before income tax expense	$	81,173		$	72,992
Income tax expense	17,552			22,519
Effective tax rate	21.6		%	30.9		%

The difference between the Company's effective tax rates for the three months ended March 31, 2018 and 2017 and the U.S. statutory tax rates of 21% and 35%, respectively, primarily relates to tax-exempt income, non-deductible expenses, state income taxes (net of federal income tax benefit), and the recognition of tax credits. The effective tax rate may vary significantly due to fluctuations in the amount and source of pretax income, changes in amounts of non-deductible expenses, and timing of the recognition of tax credits.

Provisional amounts in effective tax rate

On December 22, 2017, President Trump signed the Tax Cuts and Jobs Act (the "Tax Act") into law. Under ASC 740, the effects of changes in tax rates and laws are recognized in the period in which the new legislation is enacted. In the case of U.S. federal income taxes, the enactment date is the date the bill becomes law (i.e., upon presidential signature). Among other provisions, the most significant to the Company is the reduction of the corporate income tax rate from 35% to 21%. With respect to the legislation, the Company recognized a provisional one-time increase in tax expense of $51.0 million as of December 31, 2017 due to a re-measurement of deferred tax assets and liabilities resulting from the decrease in the corporate income tax rate. During the three months ended March 31, 2018, the Company made no adjustment to the provisional amounts recorded at December 31, 2017, and the accounting for the tax effects of the Tax Act remain incomplete as of March 31, 2018. The Company is in the process of analyzing certain aspects of the Tax Act, obtaining additional information, and refining its calculations, which could potentially affect the measurement of these balances. Information which could result in adjustment to the provisional amount includes, but is not limited to, provisional deferred tax amounts acquired in the Sabadell United acquisition, elections or changes in IRS tax methods, and further analysis of tax positions. Our estimates may also be affected as we gain a more thorough understanding of the Tax Act. Consistent with the guidance provided under ASC 740, the Company recorded impacts from enactment of the Tax Act in the fourth quarter of 2017 subject to Staff Accounting Bulletin 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act ("SAB 118"). SAB 118 provides a measurement period not to extend beyond one year of the enactment date to adjust the accounting for certain elements of the tax reform.

XML

Shareholders' Equity, Capital Ratios and Other Regulatory Matters

3 Months Ended

Mar. 31, 2018

Banking and Thrift [Abstract]

Shareholders' Equity, Capital Ratios and Other Regulatory Matters

SHAREHOLDERS' EQUITY, CAPITAL RATIOS AND OTHER REGULATORY MATTERS

Preferred Stock

The following table presents a summary of the Company's non-cumulative perpetual preferred stock:

							March 31, 2018		December 31, 2017
	Issuance Date	Earliest Redemption Date	Annual Dividend Rate		Liquidation Amount		Carrying Amount		Carrying Amount
(Dollars in thousands)
Series B Preferred Stock	8/5/2015	8/1/2025	6.625	%	$	80,000	$	76,812	$	76,812
Series C Preferred Stock	5/9/2016	5/1/2026	6.600	%	57,500		55,285		55,285
					$	137,500	$	132,097	$	132,097

Common Stock

During the second quarter of 2016, the Company's Board of Directors authorized the repurchase of up to 950,000 shares of IBERIABANK Corporation's outstanding common stock. Stock repurchases under this program will be made from time to time, on the open market or in privately negotiated transactions. The timing of these repurchases will depend on market conditions and other requirements. The share repurchase program does not obligate the Company to repurchase any dollar amount or number of shares, and expires during the second quarter of 2018. The program may be extended, modified, suspended, or discontinued at any time. The Company did not repurchase any shares during the quarter ended March 31, 2018. At March 31, 2018, the remaining common shares that could be repurchased under the plan approved by the Board was 747,494 shares. Subsequent to quarter end and through May 7, 2018, the Company repurchased180,000common shares for approximately$13.7 million.

On March 23, 2018, as part of the Gibraltar acquisition, the Company issued 2,787,773 shares of common stock. The aggregate value of the acquisition consideration paid by the Company at the time of closing was approximately $214.7 million based on the Company's closing common stock price of $77.00 per share on March 23, 2018. Gibraltar common shareholders received 1.9749 shares of IBERIABANK Corporation common stock for each outstanding share of Gibraltar common stock. Refer to Note 3, Acquisition Activity, for further detail regarding the Gibraltar acquisition.

Regulatory Capital

The Company and IBERIABANK are subject to various regulatory capital requirements administered by the federal and state banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy regulations and the regulatory framework for prompt corrective action, the Company and IBERIABANK, as applicable, must meet specific capital guidelines that involve quantitative measures of their assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors.

Management believes that, as of March 31, 2018, the Company and IBERIABANK met all capital adequacy requirements to which they are subject.

As of March 31, 2018, the most recent notification from the FRB categorized IBERIABANK as well-capitalized under the regulatory framework for prompt corrective action (the prompt corrective action requirements are not applicable to the Company). To be categorized as well-capitalized, an institution must maintain minimum total risk-based, Tier 1 risk-based and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since the notification that management believes have changed that categorization.

The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2018 and December 31, 2017 are presented in the following tables.

(Dollars in thousands)	March 31, 2018
	Minimum				Well-Capitalized		Actual
	Amount		Ratio		Amount	Ratio	Amount		Ratio
Tier 1 Leverage
Consolidated	$	1,076,933	4.00	%	N/A	N/A	$	2,685,315	9.97	%
IBERIABANK	1,074,579		4.00		1,343,223	5.00	2,640,916		9.83
Common Equity Tier 1 (CET1) (1)
Consolidated	$	1,067,284	4.50	%	N/A	N/A	$	2,553,218	10.77	%
IBERIABANK	1,065,059		4.50		1,538,418	6.50	2,640,916		11.16
Tier 1 Risk-Based Capital (1)
Consolidated	$	1,423,046	6.00	%	N/A	N/A	$	2,685,315	11.32	%
IBERIABANK	1,420,078		6.00		1,893,437	8.00	2,640,916		11.16
Total Risk-Based Capital (1)
Consolidated	$	1,897,394	8.00	%	N/A	N/A	$	2,959,774	12.48	%
IBERIABANK	1,893,437		8.00		2,366,797	10.00	2,798,875		11.83

	December 31, 2017
	Minimum				Well-Capitalized		Actual
	Amount		Ratio		Amount	Ratio	Amount		Ratio
Tier 1 Leverage
Consolidated	$	1,073,381	4.00	%	N/A	N/A	$	2,509,496	9.35	%
IBERIABANK	1,070,789		4.00		1,338,487	5.00	2,437,275		9.10
Common Equity Tier 1 (CET1) (1)
Consolidated	$	1,011,732	4.50	%	N/A	N/A	$	2,377,398	10.57	%
IBERIABANK	1,009,553		4.50		1,458,243	6.50	2,437,275		10.86
Tier 1 Risk-Based Capital (1)
Consolidated	$	1,348,977	6.00	%	N/A	N/A	$	2,509,496	11.16	%
IBERIABANK	1,346,070		6.00		1,794,760	8.00	2,437,275		10.86
Total Risk-Based Capital (1)
Consolidated	$	1,798,635	8.00	%	N/A	N/A	$	2,780,095	12.37	%
IBERIABANK	1,794,760		8.00		2,243,450	10.00	2,591,374		11.55

⁽¹⁾ Minimum capital ratios are subject to a capital conservation buffer. In order to avoid limitations on distributions, including dividend payments, and certain discretionary bonus payments to executive officers, an institution must hold a capital conservation buffer above its minimum risk-based capital requirements. This capital conservation buffer is calculated as the lowest of the differences between the actual CET1 ratio, Tier 1 Risk-Based Capital Ratio, and Total Risk-Based Capital ratio and the corresponding minimum ratios. At March 31, 2018, the required minimum capital conservation buffer was 1.875%, and will increase by 0.625% and be fully phased-in on January 1, 2019 at 2.50%. At March 31, 2018, the capital conservation buffers of the Company and IBERIABANK were 4.48% and 3.83%, respectively.

XML

Earnings Per Share

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Earnings Per Share

EARNINGS PER SHARE

Share-based payment awards that entitle holders to receive non-forfeitable dividends before vesting are considered participating securities that are included in the calculation of earnings per share using the two-class method. The two-class method is an earnings allocation formula under which earnings per share is calculated for common stock and participating securities according to dividends declared and participating rights in undistributed earnings. Under this method, all earnings, distributed and undistributed, are allocated to common shares and participating securities based on their respective rights to receive dividends.

The following table presents the calculation of basic and diluted earnings per share for the periods indicated.

	Three Months Ended March 31,
(In thousands, except per share data)	2018			2017
Earnings per common share - basic:
Net income	$	63,621		$	50,473
Less: Preferred stock dividends	3,598			3,599
Less: Dividends and undistributed earnings allocated to unvested restricted shares	639			346
Net income allocated to common shareholders - basic	$	59,384		$	46,528
Weighted average common shares outstanding	53,616			46,123
Earnings per common share - basic	1.11			1.01
Earnings per common share - diluted:
Net income allocated to common shareholders - basic	$	59,384		$	46,528
Adjustment for undistributed earnings allocated to unvested restricted shares	(18		)	(37		)
Net income allocated to common shareholders - diluted	$	59,366		$	46,491
Weighted average common shares outstanding	53,616			46,123
Dilutive potential common shares	351			373
Weighted average common shares outstanding - diluted	53,967			46,496
Earnings per common share - diluted	$	1.10		$	1.00

For the three months ended March 31, 2018, and 2017, the calculations for basic shares outstanding exclude the weighted average shares owned by the Recognition and Retention Plan (“RRP”) of 606,442 and 406,896, respectively.

The effects from the assumed exercises of 156,737 and 70,456 stock options were not included in the computation of diluted earnings per share for the three months ended March 31, 2018 and 2017, respectively, because such amounts would have had an antidilutive effect on earnings per common share.

XML

Share-Based Compensation

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-Based Compensation

SHARE-BASED COMPENSATION

The Company has various types of share-based compensation plans that permit the granting of awards in the form of stock options, restricted stock, restricted share units and phantom stock. These plans are administered by the Compensation Committee of the Board of Directors, which selects persons eligible to receive awards and determines the terms, conditions and other provisions of the awards. At March 31, 2018, awards of 1,166,797 shares could be made under approved incentive compensation plans. The Company issues shares to fulfill stock option exercises and restricted share units and restricted stock awards vesting from available authorized common shares. At March 31, 2018, the Company believes there are adequate authorized shares to satisfy anticipated stock option exercises and restricted share unit and restricted stock award vesting.

Stock option awards

The Company issues stock options under various plans to directors, officers and other key employees. The option exercise price cannot be less than the fair value of the underlying common stock as of the date of the option grant and the maximum option term cannot exceed ten years.

The following table represents the activity related to stock options during the periods indicated:

	Number of Shares		Weighted Average Exercise Price
Outstanding options, December 31, 2016	721,538		$	55.38
Granted	70,433		85.52
Exercised	(24,457	)	53.85
Forfeited or expired	(12,539	)	75.77
Outstanding options, March 31, 2017	754,975		$	57.90
Exercisable options, March 31, 2017	509,347		$	55.78
Outstanding options, December 31, 2017	686,366		$	58.24
Granted	92,162		82.20
Exercised	(21,212	)	52.10
Forfeited or expired	(14,513	)	65.27
Outstanding options, March 31, 2018	742,803		$	61.25
Exercisable options, March 31, 2018	519,496		$	56.53

The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. The following weighted-average assumptions were used for option awards issued during the following periods:

	For the Three Months Ended March 31,
	2018			2017
Expected dividends	1.8		%	1.7		%
Expected volatility	24.3		%	24.9		%
Risk-free interest rate	2.7		%	2.1		%
Expected term (in years)	5.7			5.6
Weighted-average grant-date fair value	$	18.36		$	18.75

The assumptions above are based on multiple factors, including historical stock option exercise patterns and post-vesting employment termination behaviors, expected future exercise patterns and the expected volatility of the Company’s stock price.

The following table represents the compensation expense that is included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to stock options for the following periods:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to stock options	$	312	$	444
Income tax benefit related to stock options	23		68

At March 31, 2018, there was $2.8 million of unrecognized compensation expense related to stock options that is expected to be recognized over a weighted-average period of 3.2 years.

Restricted stock awards

The Company issues restricted stock under various plans for certain officers and directors. The restricted stock awards may not be sold or otherwise transferred until certain restrictions have lapsed. The holders of the restricted stock receive dividends and have the right to vote the shares. The compensation expense for these awards is determined based on the market price of the Company's common stock at the date of grant applied to the total number of shares granted and is recognized over the vesting period (generally three to five years). As of March 31, 2018 and 2017, unrecognized share-based compensation expense associated with these awards totaled $39.0 million and $21.4 million, respectively. The unrecognized compensation expense related to restricted stock awards at March 31, 2018 is expected to be recognized over a weighted-average period of 1.5 years.

Restricted share units

During the first three months of 2018 and 2017, the Company issued restricted share units to certain of its executive officers. Restricted share units vest after the end of a three year performance period, based on satisfaction of the market and performance conditions set forth in the restricted share unit agreements. Recipients do not possess voting or investment power over the common stock underlying such units until vesting. The grant date fair value of these restricted share units is the same as the value of the corresponding number of shares of common stock, adjusted for assumptions surrounding the market-based conditions contained in the respective agreements. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017, for further discussion of restricted share units with market or performance conditions.

The following table represents the compensation expense that was included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to restricted stock awards and restricted share units for the periods indicated:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to restricted stock awards and restricted share units	$	4,422	$	3,277
Income tax benefit related to restricted stock awards and restricted share units	929		1,147

The following table represents unvested restricted stock award and restricted share unit activity for the following periods:

	For the Three Months Ended March 31,
	2018		2017
Number of shares at beginning of period	738,187		543,258
Granted	199,958		146,175
Forfeited	(43,405	)	(4,105	)
Vested	(115,877	)	(157,753	)
Number of shares at end of period	778,863		527,575

Phantom stock awards

The Company issues phantom stock awards to certain key officers and employees. The awards are subject to a vesting period of five years and are paid out in cash upon vesting. The amount paid per vesting period is calculated as the number of vested “share equivalents” multiplied by the closing market price of a share of the Company’s common stock on the vesting date. Share equivalents are calculated on the date of grant as the total award’s dollar value divided by the closing market price of a share of the Company’s common stock on the grant date. Award recipients are also entitled to a “dividend equivalent” on each unvested share equivalent held by the award recipient. A dividend equivalent is a dollar amount equal to the cash dividends that the participant would have been entitled to receive if the participant’s share equivalents were issued in shares of common stock. Dividend equivalents are reinvested as share equivalents that will vest and be paid out on the same date as the underlying share equivalents on which the dividend equivalents were paid. The number of share equivalents accumulated with a dividend equivalent is determined by dividing the aggregate of dividend equivalents paid on the unvested share equivalents by the closing price of a share of the Company’s common stock on the dividend payment date.

The following table indicates compensation expense recorded for phantom stock based on the number of share equivalents vested at March 31 of the periods indicated and the current market price of the Company’s stock at that time:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to phantom stock	$	2,996	$	3,053

The following table represents phantom stock award activity during the periods indicated.

(Dollars in thousands)	Number of share equivalents (1)		Value of share equivalents (2)
Balance, December 31, 2016	472,830		$	39,600
Granted	96,897		7,665
Forfeited share equivalents	(5,330	)	422
Vested share equivalents	(143,643	)	12,024
Balance, March 31, 2017	420,754		$	33,282
Balance, December 31, 2017	393,844		$	30,523
Granted	129,234		10,080
Forfeited share equivalents	(24,460	)	1,908
Vested share equivalents	(121,758	)	10,187
Balance, March 31, 2018	376,860		$	29,395

⁽¹⁾  Number of share equivalents includes all reinvested dividend equivalents for the periods indicated.

⁽²⁾  Except for share equivalents at the beginning of each period, which are based on the value at that time, and vested share payments, which are based on the cash paid at the time of vesting, the value of share equivalents is calculated based on the market price of the Company’s stock at the end of the respective periods. The market price of the Company’s stock was $78.00 and $79.10 on March 31, 2018, and 2017, respectively.

XML

Fair Value Measurements

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE MEASUREMENTS

Recurring fair value measurements

The Company has segregated all financial assets and liabilities that are measured at fair value on a recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to estimate the fair value at the measurement date in the tables below. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017, for a description of how fair value measurements are determined.

	March 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Securities available for sale	$	—	$	4,542,486	$	—	$	4,542,486
CRA and Community Development Investment Funds	—		9,801		—		9,801
Mortgage loans held for sale	—		110,348		—		110,348
Derivative instruments	—		17,072		—		17,072
Total	$	—	$	4,679,707	$	—	$	4,679,707
Liabilities
Derivative instruments	$	—	$	32,154	$	—	$	32,154
Total	$	—	$	32,154	$	—	$	32,154
	December 31, 2017
	Level 1		Level 2		Level 3		Total
Assets
Securities available for sale	$	—	$	4,590,062	$	—	$	4,590,062
Mortgage loans held for sale	—		134,916		—		134,916
Derivative instruments	—		31,265		—		31,265
Total	$	—	$	4,756,243	$	—	$	4,756,243
Liabilities
Derivative instruments	$	—	$	25,154	$	—	$	25,154
Total	$	—	$	25,154	$	—	$	25,154

During the three months ended March 31, 2018, there were no transfers between the Level 1 and Level 2 fair value categories.

Non-recurring fair value measurements

The Company has segregated all assets and liabilities that are measured at fair value on a non-recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date in the tables below.

	March 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Loans	$	—	$	—	$	85,269	$	85,269
OREO, net	—		—		2,234		2,234
Total	$	—	$	—	$	87,503	$	87,503
	December 31, 2017
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Loans	$	—	$	—	$	71,210	$	71,210
OREO, net	—		—		3,029		3,029
Total	$	—	$	—	$	74,239	$	74,239

The tables above exclude the initial measurement of assets and liabilities that were acquired as part of the Sabadell United acquisition in July of 2017 and the Gibraltar acquisition in March of 2018. These assets and liabilities were recorded at their fair value upon acquisition in accordance with U.S. GAAP and were not re-measured during the periods presented unless specifically required by U.S. GAAP. Acquisition date fair values represent either Level 2 fair value measurements (investment securities, deposits, property, equipment, and debt) or Level 3 fair value measurements (loans and core deposit intangible assets.) Refer to Note 3, Acquisition Activity, for further detail regarding the Sabadell United and Gibraltar acquisitions.

In accordance with the provisions of ASC Topic 310, the Company records certain loans considered impaired at their estimated fair value. A loan is considered impaired if it is probable the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Fair value is measured at the estimated fair value of the collateral for collateral-dependent loans.

The Company did not record any liabilities at fair value for which measurement of the fair value was made on a non-recurring basis as of March 31, 2018 and December 31, 2017.

Fair value option

The Company has elected the fair value option for certain originated residential mortgage loans held for sale, which allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to hedge them without the burden of complying with the requirements for hedge accounting. The Company has $17.0 million and $15.0 million of mortgage loans held for investment for which the fair value option was elected upon origination and continue to be accounted for at fair value at March 31, 2018 and December 31, 2017, respectively. Net gains (losses) resulting from the change in fair value of these loans that were recorded in mortgage income in the consolidated statements of comprehensive income for the three months ended March 31, 2018 and 2017 totaled $(749) thousand and $(409) thousand, respectively.

The following table summarizes the difference between the aggregate fair value and the aggregate unpaid principal balance for mortgage loans held for sale measured at fair value:

	March 31, 2018						December 31, 2017
(Dollars in thousands)	Aggregate Fair Value		Aggregate Unpaid Principal		Aggregate Fair Value Less Unpaid Principal		Aggregate Fair Value		Aggregate Unpaid Principal		Aggregate Fair Value Less Unpaid Principal
Mortgage loans held for sale, at fair value	$	110,348	$	107,849	$	2,499	$	134,916	$	131,276	$	3,640

Interest income on mortgage loans held for sale is recognized based on contractual rates and is reflected in interest income on loans held for sale in the consolidated statements of comprehensive income. Net gains (losses) resulting from the change in fair value of these loans that were recorded in mortgage income in the consolidated statements of comprehensive income for the three months ended March 31, 2018 and 2017 totaled $(1.1) million and $839 thousand, respectively. The changes in fair value are mostly offset by economic hedging activities, with an insignificant portion of these changes attributable to changes in instrument-specific credit risk.

XML

Fair Value of Financial Instruments

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

FAIR VALUE OF FINANCIAL INSTRUMENTS

The estimated fair value of a financial instrument is the current amount that would be exchanged between willing parties, other than in a forced liquidation. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. ASC Topic 825, Financial Instruments, excludes certain financial instruments and all non-financial instruments from its disclosure requirements. Consequently, the aggregate fair value amounts presented may not necessarily represent the underlying fair value of the Company.

The carrying amount and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are included in the tables below. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017 for a description of how fair value measurements are determined, except for loans, amended upon implementation of ASU 2016-01, Financial Statements - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. See Note 2, Recent Accounting Pronouncements, in this Report for a description of how the fair value measurement is determined for loans beginning January 1, 2018.

		March 31, 2018
(Dollars in thousands)		Carrying  Amount		Fair Value		Level 1		Level 2		Level 3
Measurement Category
Fair Value
	Financial Assets
	Securities available for sale	$	4,542,486	$	4,542,486	$	—	$	4,542,486	$	—
	CRA and Community Development Investment Funds	9,801		9,801		—		9,801		—
	Mortgage loans held for sale	110,348		110,348		—		110,348		—
	Derivative instruments	17,072		17,072		—		17,072		—
	Financial Liabilities
	Derivative instruments	32,154		32,154		—		32,154		—
Amortized Cost
	Financial Assets
	Cash and cash equivalents	$	564,092	$	564,092	$	564,092	$	—	$	—
	Securities held to maturity	224,241		219,868		—		219,868		—
	Loans and leases, net of unearned income and allowance for loan and lease losses	21,561,563		21,495,639		—		—		21,495,639
	Financial Liabilities
	Deposits	22,971,192		22,970,554		—		22,970,554		—
	Short-term borrowings	900,496		900,496		525,496		375,000		—
	Long-term debt	1,449,302		1,429,335		—		—		1,429,335

		December 31, 2017
(Dollars in thousands)		Carrying Amount		Fair Value		Level 1		Level 2		Level 3
Measurement Category
Fair Value
	Financial Assets
	Securities available for sale	$	4,590,062	$	4,590,062	$	—	$	4,590,062	$	—
	Mortgage loans held for sale	134,916		134,916		—		134,916		—
	Derivative instruments	31,265		31,265		—		31,265		—
	Financial Liabilities
	Derivative instruments	25,154		25,154		—		25,154		—
Amortized Cost
	Financial Assets
	Cash and cash equivalents	$	625,724	$	625,724	$	625,724	$	—	$	—
	Securities held to maturity	227,318		227,964		—		227,964		—
	Loans and leases, net of unearned income and allowance for loan and lease losses	19,937,290		19,826,857		—		—		19,826,857
	Financial Liabilities
	Deposits	21,466,717		21,460,782		—		21,460,782		—
	Short-term borrowings	991,297		991,297		516,297		475,000		—
	Long-term debt	1,495,835		1,476,899		—		—		1,476,899

The fair value estimates presented herein are based upon pertinent information available to management as of March 31, 2018 and December 31, 2017. Although management is not aware of any factors that would significantly affect the estimated fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since that date and, therefore, current estimates of fair value may differ significantly from the amounts presented herein.

XML

Business Segments

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Business Segments

BUSINESS SEGMENTS

Each of the Company’s reportable operating segments serves the specific needs of the Company’s customers based on the products and services it offers. The reportable segments are based upon those revenue-producing components for which separate financial information is produced internally and primarily reflect the manner in which resources are allocated and performance is assessed. Further, the reportable operating segments are also determined based on the quantitative thresholds prescribed within ASC Topic 280, Segment Reporting, and consideration of the usefulness of the information to the users of the consolidated financial statements.

The Company reports the results of its operations through three reportable segments: IBERIABANK, Mortgage, and LTC. The IBERIABANK segment represents the Company’s commercial and retail banking functions, including its lending, investment, and deposit activities. IBERIABANK also includes the Company’s wealth management, capital markets, and other corporate functions. The Mortgage segment represents the Company’s origination, funding, and subsequent sale of one-to-four family residential mortgage loans. The LTC segment represents the Company’s title insurance and loan closing services.

Certain expenses not directly attributable to a specific reportable segment are allocated to segments based on pre-determined methods that reflect utilization. Also within IBERIABANK are certain reconciling items that translate reportable segment results into consolidated results. The following tables present certain information regarding our operations by reportable segment, including a reconciliation of segment results to reported consolidated results for the periods presented. Reconciling items between segment results and reported results include:

• Elimination of interest income and interest expense representing interest earned by IBERIABANK on interest-bearing checking accounts held by related companies, as well as the elimination of the related deposit balances at the IBERIABANK segment;

• Elimination of investment in subsidiary balances on certain operating segments included in total and average segment assets; and

• Elimination of intercompany due to and due from balances on certain operating segments that are included in total and average segment assets.

	Three Months Ended March 31, 2018
(Dollars in thousands)	IBERIABANK			Mortgage			LTC			Consolidated
Interest and dividend income	$	268,775		$	1,767		$	1		$	270,543
Interest expense	37,654			—			—			37,654
Net interest income	231,121			1,767			1			232,889
Provision for/(reversal of) loan and lease losses	7,991			(5		)	—			7,986
Mortgage income	—			9,595			—			9,595
Title revenue	—			—			5,027			5,027
Other non-interest income	29,906			38			—			29,944
Allocated expenses	(1,479		)	1,166			313			—
Non-interest expense	171,816			11,916			4,564			188,296
Income/(loss) before income tax expense	82,699			(1,677		)	151			81,173
Income tax expense/(benefit)	18,540			(410		)	(578		)	17,552
Net income/(loss)	$	64,159		$	(1,267	)	$	729		$	63,621
Total loans, leases, and loans held for sale, net of unearned income	$	21,652,223		$	164,215		$	—		$	21,816,438
Total assets	29,243,983			205,497			23,157			29,472,637
Total deposits	22,959,061			12,131			—			22,971,192
Average assets	27,924,587			185,742			21,890			28,132,219

	Three Months Ended March 31, 2017
(Dollars in thousands)	IBERIABANK			Mortgage			LTC			Consolidated
Interest and dividend income	$	190,823		$	1,709		$	1		$	192,533
Interest expense	19,715			—			—			19,715
Net interest income	171,108			1,709			1			172,818
Provision for/(reversal of) loan and lease losses	6,158			(4		)	—			6,154
Mortgage income	—			14,115			—			14,115
Title revenue	—			—			4,741			4,741
Other non-interest income	26,284			(10		)	(6		)	26,268
Allocated expenses	(2,174		)	1,656			518			—
Non-interest expense	119,429			15,167			4,200			138,796
Income/(loss) before income tax expense	73,979			(1,005		)	18			72,992
Income tax expense/(benefit)	22,829			(322		)	12			22,519
Net income/(loss)	$	51,150		$	(683	)	$	6		$	50,473
Total loans, leases, and loans held for sale, net of unearned income	$	15,072,661		$	181,874		$	—		$	15,254,535
Total assets	21,774,586			209,911			23,982			22,008,479
Total deposits	17,306,328			5,937			—			17,312,265
Average assets	21,550,930			286,694			23,877			21,861,501

XML

Commitments and Contingencies

3 Months Ended

Mar. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

COMMITMENTS AND CONTINGENCIES

Off-balance sheet commitments

In the normal course of business, to meet the financing needs of its customers, the Company is a party to credit-related financial instruments, with risk not reflected in the consolidated financial statements. These financial instruments include commitments to extend credit, standby letters of credit, and commercial letters of credit. Such commitments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheets. The credit policies used for these commitments are consistent with those used for on-balance sheet instruments. The Company’s exposure to credit loss in the event of non-performance by its customers under such commitments or letters of credit represents the contractual amount of the financial instruments as indicated in the table below. At both March 31, 2018 and December 31, 2017, the fair value of guarantees under commercial and standby letters of credit was $2.1 million. This fair value will decrease as the existing commercial and standby letters of credit approach their expiration dates.

At March 31, 2018 and December 31, 2017, respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Commitments to grant loans	$	319,318	$	342,305
Unfunded commitments under lines of credit	6,340,135		6,060,034
Commercial and standby letters of credit	211,070		210,002
Reserve for unfunded lending commitments	13,432		13,208

Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee by the borrower. Since many of the commitments are expected to be drawn upon, the total commitment amounts generally represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral, if any, is based on management’s credit evaluation of the customer.

Unfunded commitments under commercial lines of credit, revolving credit lines, and overdraft protection agreements are commitments for possible future extensions of credit to existing customers. Many of these types of commitments do not contain a specified maturity date and may not be drawn upon to the total extent to which the Company is committed. See Note 6, Allowance for Credit Losses and Credit Quality, for additional information related to the Company’s reserve for unfunded lending commitments.

Commercial and standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. These guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper issuance, bond financing, and similar transactions. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. When necessary they are collateralized, generally in the form of marketable securities and cash equivalents.

Legal proceedings

The nature of the business of the Company’s banking and other subsidiaries ordinarily results in a certain amount of claims, litigation, investigations, and legal and administrative cases and proceedings, which are considered incidental to the normal conduct of business. Some of these claims are against entities or assets of which the Company is a successor or acquired in business acquisitions. The Company has asserted defenses to these claims and, with respect to such legal proceedings, intends to continue to defend itself vigorously, litigating or settling cases according to management’s judgment as to what is in the best interest of the Company and its shareholders.

In July of 2016, the Company received a subpoena from the Office of Inspector General of the U.S. Department of Housing and Urban Development (“HUD”) requesting information on certain previously originated loans insured by the Federal Housing Administration ("FHA") as well as other documents regarding the Company's FHA-related policies and practices. After the Company complied with the subpoena, attorneys from the Department of Justice (“DOJ”) informed the Company in late March of 2017 that a civil qui tam suit had been filed against the Company in federal court involving the subject matter of the HUD subpoena. The HUD lawsuit was settled on December 11, 2017 in the amount of $11.7 million. On February 2, 2018, IBERIABANK filed a lawsuit in the United States District Court for the Eastern District of Louisiana (New Orleans) against Illinois Union Insurance Company and Travelers Casualty and Surety Company of America in an effort to recover the $11.7 million it paid to settle the HUD matter. IBERIABANK filed that lawsuit to recover the insurance proceeds to which it claims to be entitled under certain Bankers’ Professional Liability insurance policies issued by defendants Illinois Union and Travelers. More Specifically, IBERIABANK alleges that the insurers have failed to honor their obligations under the policies to pay IBERIABANK’s losses in connection with the $11.7 million settlement of disputed allegations relating to IBERIABANK’s professional services in connection with certain mortgage loans insured by the FHA.

The Company assesses its liabilities and contingencies in connection with outstanding legal proceedings utilizing the latest information available. Where it is probable that the Company will incur a loss and the amount of the loss can be reasonably estimated, the Company records a liability in its consolidated financial statements. These legal reserves may be increased or decreased to reflect any relevant developments on a quarterly basis. Where a loss is not probable or the amount of loss is not estimable, the Company does not accrue legal reserves. While the outcome of legal proceedings is inherently uncertain, based on information currently available and available insurance coverage, the Company’s management believes that it has established appropriate legal reserves. Any incremental liabilities arising from pending legal proceedings are not expected to have a material adverse effect on the Company’s consolidated financial position, consolidated results of operations, or consolidated cash flows. However, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the Company’s consolidated financial position, consolidated results of operations, or consolidated cash flows.

As of the date of this filing, the Company believes the amount of losses associated with legal proceedings that it is reasonably possible to incur above amounts already accrued is not material.

XML

Related Party Transactions

3 Months Ended

Mar. 31, 2018

Related Party Transactions [Abstract]

Related Party Transactions

RELATED PARTY TRANSACTIONS

In the ordinary course of business, the Company may execute transactions with various related parties. Examples of such transactions may include lending or deposit arrangements, transfers of financial assets, services for administrative support, and other miscellaneous items.

The Company has granted loans to executive officers and directors and their affiliates. These loans, including the related principal additions, principal payments, and unfunded commitments are not material to the consolidated financial statements at March 31, 2018 and December 31, 2017. There were no outstanding loans to related parties classified as non-accrual, past due, or troubled debt restructurings at March 31, 2018.

Deposits from related parties held by the Company were not material at March 31, 2018 and December 31, 2017.

XML

Basis of Presentation (Policies)

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

Reclassification

Certain amounts reported in prior periods have been reclassified to conform to the current period presentation. These reclassifications did not have a material effect on previously reported consolidated financial statements.

Concentration of Credit Risks

Concentrations of Credit Risk

Most of the Company’s business activity is with customers located in the southeastern United States. The Company’s lending activity is concentrated in its market areas within those states. The Company has emphasized originations of commercial loans and private banking loans, defined as loans to higher net worth clients. Repayments on loans are expected to come from cash flows of the borrower and/or guarantor. Losses on secured loans are limited by the net realizable value of the collateral upon default of the borrowers and guarantor support. The Company believes it does not have any excessive concentrations to any one industry, loan type, or customer.

Recent Accounting Pronouncements

RECENT ACCOUNTING PRONOUNCEMENTS

Pronouncements adopted during the three months ended March 31, 2018:

ASU No. 2014-09

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which implements a common revenue standard and clarifies the principles used for recognizing revenue. The amendments in the ASU clarify that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.

Revenue from Contracts with Customers

The majority of the Company’s income streams (e.g., interest and dividend income and mortgage income) are accounted for in accordance with GAAP literature outside the scope of ASC 606, Revenue from Contracts with Customers. Details regarding income recognition for interest and non-interest streams can be found throughout the Company’s 2017 10-K (including Note 1 - Summary of Significant Accounting Policies). Impairment losses recognized against certain receivables (e.g., NSF fees) and capitalized costs (e.g., sales commissions) associated with contracts within the scope of ASC 606 are immaterial.

Non-interest income from service charges on deposit accounts, broker commissions, ATM/debit card fee income, credit card and merchant-related income (e.g., interchange fees), and transactional income from traditional banking services (part of other non-interest income) are the significant income streams within the scope of ASC 606 associated with the IBERIABANK reportable segment. Non-interest income from title revenue is associated with the LTC reportable segment.

Recognition of Revenue from Contracts with Customers

The Company enters into various contracts with customers to provide traditional banking services, including asset management, on a routine basis. The Company’s performance obligations are generally service-related and provided on a daily or monthly basis. The Company does not typically have performance obligations which extend beyond a reporting period. The performance obligations are generally satisfied upon completion of service (i.e., as services are rendered) and the fees are collected at such time, or shortly thereafter. The fees are readily determinable and allocated individually to each service. It is not typical for contracts to require significant judgment to determine the transaction price. Some contracts contain variable consideration; however, the variable consideration is generally constrained (not estimable) as it is based on the occurrence or nonoccurence of a contingent event (or another constraint in some circumstances). The Company generally records the variable consideration when the contingent event occurs and the fee is determinable.

The Company provides some services for customers in which it acts in an agent capacity, but generally acts in a principal capacity. Payment terms and conditions vary slightly amongst services; however, amounts are generally invoiced and due or collected by the Company within 30 days, although some fees may be prepaid. The Company bills the customer periodically as performance obligations are satisfied for most services. Therefore, revenue for services provided is generally recognized in the amount invoiced (except in circumstances of prepayment) as that amount corresponds directly to the value of the Company’s performance. In the normal course of business, the Company does not generally grant refunds for services provided. As such, the Company does not establish provisions for estimated returns.

Title revenue associated with services provided by LTC, as well as broker commissions, ATM/debit card fee income, credit card and merchant-related income (e.g., interchange fees), and transactional fees from traditional banking services generated within IBERIABANK are generally recognized at the point-in-time the services are provided. The Company has determined this recognition to be appropriate as, upon completion of services, the Company has completed its performance obligations, has a present right to payment (or has collected the cash), and the customer is able to obtain (or has obtained) substantially all of the benefits from the performance obligation (i.e., the provided services). Revenues from service charges on deposit accounts are recognized at the end of the monthly service period (e.g., account service charges) or the date the performance obligation is satisfied (e.g., NSF, stop payment, wire transfer, etc.), except for deposit account services performed by Treasury Management which are recognized on a monthly basis, as these services are performed over that time. Asset management fees (e.g., trust fees) are generally recognized at the end of the monthly service period, but fees are not collected until the beginning of the subsequent month, although some contracts may have quarterly terms and/or be prepaid. NSF fees which are not initially paid are subsequently recorded as “loans” (along with the overdraft balance) and remain classified as such until the amount is paid or charged-off (generally after 60 days).

Adoption of ASC 606

The Company adopted ASC 606 as of January 1, 2018 for all contracts as of the effective date. Prior period amounts have been reclassified to conform to current guidance requirements related to the net presentation of certain costs associated with interchange fees and rewards programs. The reclassification of prior period amounts reduced non-interest income and non-interest expense by an immaterial amount (approximately $2.2 million for the three months ended March 31, 2017) and had no impact on net income. There was no cumulative adjustment made to opening retained earnings as of January 1, 2018.

ASU No. 2016-01

In January 2016, the FASB issued ASU No. 2016-01, Financial Statements - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, which impacts how the Company measures certain equity investments and discloses and presents certain financial instruments through the application of the “exit price” notion.

The Company adopted the amendments beginning January 1, 2018. Under the new guidance, equity investments can no longer be classified as trading or available for sale (AFS), and related unrealized holding gains and losses can no longer be recognized in OCI. Per the ASU, such equity investments should be measured at fair value, with adjustments recognized in earnings at the end of each reporting period. As such, the Company reclassified its portfolio of equity investments (approximately $9.8 million at March 31, 2018) previously classified as AFS investment securities to “other assets.” As these equity investments were previously measured at fair value, implementation of the ASU did not impact the Company’s valuation method. In accordance with the ASU, the cumulative-effect adjustment from AOCI to retained earnings for previously recorded fair value adjustments related to these equity investments at adoption was insignificant.

The Company elected the practical expedient measurement alternative to prospectively account for other equity investments that do not have readily determinable fair values at cost less impairment plus or minus observable price changes in orderly transactions for an identical or similar investment of the same issuer. These investments are immaterial overall and are classified within “other assets” on the Company’s consolidated balance sheets.

The Company also modified its fair value methodology for loans measured at amortized cost whose fair values were previously disclosed using an “entry price” methodology to an “exit price” methodology, in accordance with the ASU. The Company’s “exit price” methodology estimates the fair value of these loans based on the present value of the future cash flows using the interest rate that would be charged for a similar loan to a borrower with similar risk at the indicated balance sheet date, adjusted for a liquidity discount based on the estimated time period to complete a sale transaction with a market participant. This change in methodology solely impacted the Company’s disclosures, and had no impact to the Company’s consolidated financial statements.

ASU No. 2016-15

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (ASC 230): Classification of Certain Cash Receipts and Cash Payments, in order to reduce current diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows.

The Company retrospectively adopted the amendments effective January 1, 2018. The adoption of these amendments did not impact the Company’s consolidated statements of cash flows.

ASU No. 2017-12

In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities, which amends the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements and enhance the transparency and understandability of hedge results.

The Company elected to early adopt the amendments effective January 1, 2018. The modified-retrospective adoption of the amendments did not impact the Company’s consolidated financial statements in the current or prior periods.

Pronouncements issued but not yet adopted:

ASU No. 2016-02

In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842). A significant amendment to existing GAAP from this ASU is the recognition of lease assets (i.e., right of use assets) and liabilities on the balance sheet for leases that are classified as operating leases by lessees. The lessor model remains similar to the current accounting model in existing GAAP. Additional amendments include, but are not limited to, the elimination of leveraged leases; modification to the definition of a lease; amendments on sale and leaseback transactions; and disclosure of additional quantitative and qualitative information.

ASU 2016-02 will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. Lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company will adopt the amendments on January 1, 2019.

The Company occupies certain banking offices and equipment under operating lease agreements, which currently are not recognized on the consolidated balance sheets. Based on the Company’s preliminary analysis of its current portfolio, the impact to the Company’s consolidated balance sheets is estimated to result in less than a 1% increase in assets and liabilities. The Company is also currently assessing the practical expedients it may elect at adoption, the final determination of the incremental borrowing rate, and the impact to regulatory capital ratios, amongst other matters associated with the ASU.

The adjustment to retained earnings is not expected to be significant based on the transition guidance associated with current sale-leaseback agreements. The Company also anticipates additional disclosures to be provided at adoption.

ASU No. 2016-13

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments. The amendments introduce an impairment model that is based on expected credit losses (“ECL”), rather than incurred losses, to estimate credit losses on certain types of financial instruments (e.g., loans and held-to-maturity securities), including certain off-balance sheet financial instruments (e.g., loan commitments). The measurement of ECL should consider historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments, over the contractual term. Financial instruments with similar risk characteristics may be grouped together when estimating ECL.

The ASU also amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset through the use of an allowance to record estimated credit losses (and subsequent recoveries). Non-credit related losses will continue to be recognized through OCI.

In addition, the amendments provide for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination. The initial estimate of expected credit losses would be recognized through an ALLL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition.

ASU 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods. The amendments will be applied through a modified-retrospective approach, resulting in a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. A prospective transition approach is required for debt securities for which OTTI had been recognized before the effective date. Amounts previously recognized in AOCI as of the date of adoption that relate to improvements in cash flows expected to be collected should continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption should be recorded in earnings when received.

The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements; however, the Company has engaged third-party consultants to assist with the ASU and has developed an implementation plan.

XML

Loans (Tables)

3 Months Ended

Mar. 31, 2018

Receivables [Abstract]

Schedule of Non-Covered and Covered Loans

Loans and leases consist of the following for the periods indicated:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Commercial loans and leases:
Real estate- construction	$	1,199,625	$	1,240,396
Real estate- owner-occupied	2,612,244		2,529,885
Real estate- non-owner-occupied	5,437,082		5,167,949
Commercial and industrial (1)	5,325,682		5,135,067
	14,574,633		14,073,297
Residential mortgage loans:	3,971,067		3,056,352
Consumer loans:
Home equity	2,421,186		2,292,275
Indirect automobile	50,671		62,693
Credit card	93,261		96,368
Other	595,272		497,196
	3,160,390		2,948,532
Total	$	21,706,090	$	20,078,181

⁽¹⁾  Includes equipment financing leases.

Schedule of Aging of Loans

The following tables provide an analysis of the aging of loans as of March 31, 2018 and December 31, 2017. Past due and non-accrual loan amounts exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans.

	March 31, 2018
	Accruing
(Dollars in thousands)	Current or Less Than 30 days Past Due		30-59 days		60-89 days		> 90 days		Total Past Due		Non-accrual		Acquired Impaired		Total
Real estate- construction	$	1,157,115	$	842	$	129	$	—	$	971	$	2,634	$	38,905	$	1,199,625
Real estate- owner-occupied	2,474,611		4,767		3,461		—		8,228		35,144		94,261		2,612,244
Real estate- non-owner-occupied	5,319,962		7,269		2,526		6,789		16,584		9,378		91,158		5,437,082
Commercial and industrial	5,212,390		7,755		3,406		273		11,434		66,637		35,221		5,325,682
Residential mortgage	3,783,309		25,640		2,655		1,226		29,521		19,932		138,305		3,971,067
Consumer - home equity	2,309,222		11,860		3,191		—		15,051		16,383		80,530		2,421,186
Consumer - indirect automobile	48,581		1,166		175		—		1,341		743		6		50,671
Consumer - credit card	92,497		173		88		—		261		503		—		93,261
Consumer - other	585,969		2,484		706		—		3,190		2,621		3,492		595,272
Total	$	20,983,656	$	61,956	$	16,337	$	8,288	$	86,581	$	153,975	$	481,878	$	21,706,090

	December 31, 2017
	Accruing
(Dollars in thousands)	Current or Less Than 30 days Past Due		30-59 days		60-89 days		> 90 days		Total Past Due		Non-accrual		Acquired Impaired		Total
Real estate- construction	$	1,197,766	$	269	$	—	$	458	$	727	$	2,635	$	39,268	$	1,240,396
Real estate- owner-occupied	2,398,487		1,631		659		74		2,364		24,457		104,577		2,529,885
Real estate- non-owner-occupied	5,066,084		2,086		6,405		887		9,378		6,811		85,676		5,167,949
Commercial and industrial	5,014,438		5,788		5,726		146		11,660		77,823		31,146		5,135,067
Residential mortgage	2,877,048		10,083		8,136		5,317		23,536		17,387		138,381		3,056,352
Consumer - home equity	2,186,554		11,675		2,947		18		14,640		12,365		78,716		2,292,275
Consumer - indirect automobile	59,830		1,796		177		—		1,973		884		6		62,693
Consumer - credit card	95,264		140		374		—		514		590		—		96,368
Consumer - other	487,150		3,350		475		—		3,825		2,436		3,785		497,196
Total	$	19,382,621	$	36,818	$	24,899	$	6,900	$	68,617	$	145,388	$	481,555	$	20,078,181

Schedule of Carrying Amount of Loans Acquired

The tables below show the balances acquired during the first quarter of 2018 for these two subsections of the portfolio as of the acquisition date. These amounts are subject to change due to the finalization of purchase accounting adjustments.

(Dollars in thousands)	Acquired Non-Impaired Loans
Contractually required principal and interest at acquisition	$	1,695,918
Expected losses and foregone interest	(19,952		)
Cash flows expected to be collected at acquisition	1,675,966
Fair value of acquired loans at acquisition	$	1,455,085

(Dollars in thousands)	Acquired Impaired Loans
Contractually required principal and interest at acquisition	$	43,779
Non-accretable difference (expected losses and foregone interest)	(31,174		)
Cash flows expected to be collected at acquisition	12,605
Accretable yield	(2,371		)
Basis in acquired loans at acquisition	$	10,234

Summary of Changes in Accretable Yields of Acquired Loans

The following is a summary of changes in the accretable difference for all loans accounted for under ASC 310-30 during the three months ended March 31:

(Dollars in thousands)	2018			2017
Balance at beginning of period	$	152,623		$	175,054
Additions	2,371			—
Transfers from non-accretable difference to accretable yield	(279		)	2,071
Accretion	(13,154		)	(14,596		)
Changes in expected cash flows not affecting non-accretable differences (1)	9,687			1,060
Balance at end of period	$	151,248		$	163,589

⁽¹⁾  Includes changes in cash flows expected to be collected due to the impact of changes in actual or expected timing of liquidation events, modifications, changes in interest rates and changes in prepayment assumptions.

Schedule of Modified TDRs

The following table provides information on how the TDRs were modified during the periods indicated:

	Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Extended maturities	$	5,619	$	7,199
Maturity and interest rate adjustment	108		3,224
Movement to or extension of interest-rate only payments	48		1,290
Interest rate adjustment	105		—
Forbearance	12,886		1,220
Other concession(s) (1)	8,434		232
Total	$	27,200	$	13,165

⁽¹⁾  Other concessions may include covenant waivers, forgiveness of principal or interest associated with a customer bankruptcy, or a combination of any of the above concessions.

Schedule of Subsequently Defaulted TDRs

The following table presents the end of period balance for loans modified in a TDR during the periods indicated:

	Three Months Ended March 31,
	2018					2017
(In thousands, except number of loans)	Number of Loans	Pre-modification Outstanding Recorded Investment		Post-modification Outstanding Recorded Investment		Number of Loans	Pre-modification Outstanding Recorded Investment		Post-modification Outstanding Recorded Investment
Real estate- construction	1	$	1,950	$	1,049	—	$	—	$	—
Real estate- owner-occupied	2	10,691		9,324		3	3,004		2,999
Real estate- non-owner-occupied	9	1,089		1,091		7	1,867		1,855
Commercial and industrial	18	14,429		13,314		15	435		427
Residential mortgage	—	—		—		4	259		241
Consumer - home equity	14	1,809		1,795		37	6,622		6,607
Consumer - indirect	11	137		119		13	184		174
Consumer - other	10	511		508		22	867		862
Total	65	$	30,616	$	27,200	101	$	13,238	$	13,165

Information detailing TDRs that defaulted during the three-month periods ended March 31, 2018 and 2017, and were modified in the previous twelve months (i.e., the twelve months prior to the default) is presented in the following tables. The Company has defined a default as any loan with a payment that is currently past due greater than 30 days, or was past due greater than 30 days at any point during the respective periods, or since the date of modification, whichever is shorter.

	Three Months Ended March 31,
	2018			2017
(In thousands, except number of loans)	Number of Loans	Recorded Investment		Number of Loans	Recorded Investment
Real estate- construction	—	$	—	1	$	117
Real estate- owner-occupied	3	10,187		9	14,732
Real estate- non-owner-occupied	9	492		10	5,041
Commercial and industrial	29	9,708		21	4,186
Residential mortgage	6	598		22	1,793
Consumer - home equity	24	2,331		31	1,337
Consumer - indirect automobile	34	322		43	517
Consumer - other	17	1,035		25	693
Total	122	$	24,673	162	$	28,416

XML

Acquisition Activity (Tables)

3 Months Ended

Mar. 31, 2018

Gibraltar Private Bank & Trust Company [Member]

Business Acquisition [Line Items]

Schedule of Business Acquisitions

(Dollars in thousands)	Number of Shares	Amount
Equity consideration
Common stock issued	2,787,773	$	214,659
Total equity consideration		214,659
Non-equity consideration
Cash		7
Total consideration paid		214,666
Fair value of net assets assumed including identifiable intangible assets		172,136
Goodwill		$	42,530

(Dollars in thousands)	Gibraltar Fair Value (Preliminary)
Assets
Cash and cash equivalents	$	102,570
Investment securities	19,169
Equity securities	27,519
Loans	1,465,319
Core deposit intangible assets	18,529
Deferred tax asset, net	689
Other assets	14,382
Total assets acquired	$	1,648,177
Liabilities
Deposit liabilities	$	1,064,803
Long-term borrowings	405,107
Other liabilities	6,131
Total liabilities assumed	$	1,476,041

Solomon Parks Title & Escrow [Member]

Business Acquisition [Line Items]

Schedule of Business Acquisitions

(Dollars in thousands)	SolomonParks Fair Value (Preliminary)
Assets
Premise and equipment, net	$	42
Non-compete agreement	156
Title Plant investment	15
Total assets acquired	$	213
Liabilities
Contingent consideration	$	343
Total liabilities assumed	$	343

Sabadell United

Business Acquisition [Line Items]

Schedule of Business Acquisitions

(Dollars in thousands)	Number of Shares	Amount
Equity consideration
Common stock issued	2,610,304	$	211,043
Total equity consideration		211,043
Non-equity consideration
Cash		809,159
Total consideration paid		1,020,202
Fair value of net assets assumed including identifiable intangible assets		556,799
Goodwill		$	463,403

(Dollars in thousands)	Sabadell United Fair Value (Preliminary)
Assets
Cash and cash equivalents	$	318,834
Investment securities	964,123
Loans	4,025,946
Core deposit intangible assets	66,600
Deferred tax asset, net	33,469
Other assets	89,745
Total assets acquired	$	5,498,717
Liabilities
Deposit liabilities	$	4,382,780
Short-term borrowings	520,539
Other liabilities	38,599
Total liabilities assumed	$	4,941,918

Schedule of Pro Forma Information

The following table presents unaudited pro forma information as if the acquisition occurred on January 1, 2016 under the "Unaudited Pro Forma" column. The pro forma information does not necessarily reflect the results of operations that would have occurred had the Company acquired Sabadell United on January 1, 2016. Furthermore, cost savings and other business synergies related to the acquisition are not reflected in the pro forma amounts.

	Unaudited Pro Forma for
(Dollars in thousands)	Three months ended March 31, 2017
Net interest income	$	231,087
Non-interest income	54,755
Net income	43,562

XML

Investment Securities (Tables)

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities

Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, is as follows:

	March 31, 2018
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	—		$	693	$	—		$	—	$	—		$	693
U.S. Government-sponsored enterprise obligations	(419		)	29,580		(235		)	9,765		(654		)	39,345
Obligations of state and political subdivisions	(1,147		)	96,138		(3,009		)	66,404		(4,156		)	162,542
Mortgage-backed securities	(68,161		)	2,847,244		(53,054		)	1,191,233		(121,215		)	4,038,477
Other securities	(1,138		)	60,304		—			—		(1,138		)	60,304
Total securities available for sale	$	(70,865	)	$	3,033,959	$	(56,298	)	$	1,267,402	$	(127,163	)	$	4,301,361
Securities held to maturity:
Obligations of state and political subdivisions	$	(4,066	)	$	150,188	$	(54	)	$	2,976	$	(4,120	)	$	153,164
Mortgage-backed securities	(11		)	323		(1,003		)	18,187		(1,014		)	18,510
Total securities held to maturity	$	(4,077	)	$	150,511	$	(1,057	)	$	21,163	$	(5,134	)	$	171,674

	December 31, 2017
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	(254	)	$	29,744	$	(152	)	$	9,848	$	(406	)	$	39,592
Obligations of state and political subdivisions	(326		)	31,601		(1,167		)	68,609		(1,493		)	100,210
Mortgage-backed securities	(26,263		)	2,677,338		(34,765		)	1,226,058		(61,028		)	3,903,396
Other securities	(914		)	75,302		—			—		(914		)	75,302
Total securities available for sale	$	(27,757	)	$	2,813,985	$	(36,084	)	$	1,304,515	$	(63,841	)	$	4,118,500
Securities held to maturity:
Obligations of state and political subdivisions	$	(263	)	$	65,817	$	(12	)	$	3,031	$	(275	)	$	68,848
Mortgage-backed securities	(2		)	333		(648		)	19,269		(650		)	19,602
Total securities held to maturity	$	(265	)	$	66,150	$	(660	)	$	22,300	$	(925	)	$	88,450

The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following:

	March 31, 2018
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	6,824	$	—	$	—		$	6,824
U.S. Government-sponsored enterprise obligations	41,001		11		(654		)	40,358
Obligations of state and political subdivisions	267,962		1,228		(4,156		)	265,034
Mortgage-backed securities	4,277,033		279		(121,215		)	4,156,097
Other securities	75,205		106		(1,138		)	74,173
Total securities available for sale	$	4,668,025	$	1,624	$	(127,163	)	$	4,542,486
Securities held to maturity:
Obligations of state and political subdivisions	$	204,404	$	726	$	(4,120	)	$	201,010
Mortgage-backed securities	19,837		35		(1,014		)	18,858
Total securities held to maturity	$	224,241	$	761	$	(5,134	)	$	219,868

	December 31, 2017
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	41,003	$	18	$	(406	)	$	40,615
Obligations of state and political subdivisions	271,451		4,246		(1,493		)	274,204
Mortgage-backed securities	4,221,472		1,461		(61,028		)	4,161,905
Other securities	114,005		247		(914		)	113,338
Total securities available for sale	$	4,647,931	$	5,972	$	(63,841	)	$	4,590,062
Securities held to maturity:
Obligations of state and political subdivisions	$	206,736	$	1,530	$	(275	)	$	207,991
Mortgage-backed securities	20,582		41		(650		)	19,973
Total securities held to maturity	$	227,318	$	1,571	$	(925	)	$	227,964

Held-to-maturity Securities

Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, is as follows:

	March 31, 2018
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	—		$	693	$	—		$	—	$	—		$	693
U.S. Government-sponsored enterprise obligations	(419		)	29,580		(235		)	9,765		(654		)	39,345
Obligations of state and political subdivisions	(1,147		)	96,138		(3,009		)	66,404		(4,156		)	162,542
Mortgage-backed securities	(68,161		)	2,847,244		(53,054		)	1,191,233		(121,215		)	4,038,477
Other securities	(1,138		)	60,304		—			—		(1,138		)	60,304
Total securities available for sale	$	(70,865	)	$	3,033,959	$	(56,298	)	$	1,267,402	$	(127,163	)	$	4,301,361
Securities held to maturity:
Obligations of state and political subdivisions	$	(4,066	)	$	150,188	$	(54	)	$	2,976	$	(4,120	)	$	153,164
Mortgage-backed securities	(11		)	323		(1,003		)	18,187		(1,014		)	18,510
Total securities held to maturity	$	(4,077	)	$	150,511	$	(1,057	)	$	21,163	$	(5,134	)	$	171,674

	December 31, 2017
	Less Than Twelve Months					Twelve Months or More					Total
(Dollars in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	(254	)	$	29,744	$	(152	)	$	9,848	$	(406	)	$	39,592
Obligations of state and political subdivisions	(326		)	31,601		(1,167		)	68,609		(1,493		)	100,210
Mortgage-backed securities	(26,263		)	2,677,338		(34,765		)	1,226,058		(61,028		)	3,903,396
Other securities	(914		)	75,302		—			—		(914		)	75,302
Total securities available for sale	$	(27,757	)	$	2,813,985	$	(36,084	)	$	1,304,515	$	(63,841	)	$	4,118,500
Securities held to maturity:
Obligations of state and political subdivisions	$	(263	)	$	65,817	$	(12	)	$	3,031	$	(275	)	$	68,848
Mortgage-backed securities	(2		)	333		(648		)	19,269		(650		)	19,602
Total securities held to maturity	$	(265	)	$	66,150	$	(660	)	$	22,300	$	(925	)	$	88,450

The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following:

	March 31, 2018
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Treasury securities	$	6,824	$	—	$	—		$	6,824
U.S. Government-sponsored enterprise obligations	41,001		11		(654		)	40,358
Obligations of state and political subdivisions	267,962		1,228		(4,156		)	265,034
Mortgage-backed securities	4,277,033		279		(121,215		)	4,156,097
Other securities	75,205		106		(1,138		)	74,173
Total securities available for sale	$	4,668,025	$	1,624	$	(127,163	)	$	4,542,486
Securities held to maturity:
Obligations of state and political subdivisions	$	204,404	$	726	$	(4,120	)	$	201,010
Mortgage-backed securities	19,837		35		(1,014		)	18,858
Total securities held to maturity	$	224,241	$	761	$	(5,134	)	$	219,868

	December 31, 2017
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Securities available for sale:
U.S. Government-sponsored enterprise obligations	$	41,003	$	18	$	(406	)	$	40,615
Obligations of state and political subdivisions	271,451		4,246		(1,493		)	274,204
Mortgage-backed securities	4,221,472		1,461		(61,028		)	4,161,905
Other securities	114,005		247		(914		)	113,338
Total securities available for sale	$	4,647,931	$	5,972	$	(63,841	)	$	4,590,062
Securities held to maturity:
Obligations of state and political subdivisions	$	206,736	$	1,530	$	(275	)	$	207,991
Mortgage-backed securities	20,582		41		(650		)	19,973
Total securities held to maturity	$	227,318	$	1,571	$	(925	)	$	227,964

Additional Information on Securities in a Continuous Loss Position

Additional information on securities that have been in a continuous loss position for over twelve months at March 31, 2018 and December 31, 2017 is presented in the following table.

(Dollars in thousands)	March 31, 2018		December 31, 2017
Number of securities:
Mortgage-backed securities	184		181
Obligations of state and political subdivisions	28		28
Other	1		1
	213		210
Amortized Cost Basis:
Mortgage-backed securities	$	1,263,477	$	1,280,739
Obligations of state and political subdivisions	72,443		72,820
Other	10,000		10,000
	$	1,345,920	$	1,363,559
Unrealized Loss:
Mortgage-backed securities	$	54,057	$	35,412
Obligations of state and political subdivisions	3,063		1,180
Other	235		152
	$	57,355	$	36,744

Schedule of Amortized Cost and Estimated Fair Value of Investment Securities by Maturity

The amortized cost and estimated fair value of investment securities by maturity at March 31, 2018 are presented in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Weighted average yields are calculated on the basis of the yield to maturity based on the amortized cost of each security.

	Securities Available for Sale						Securities Held to Maturity
(Dollars in thousands)	Weighted Average Yield		Amortized Cost		Estimated Fair Value		Weighted Average Yield		Amortized Cost		Estimated Fair Value
Within one year or less	2.06	%	$	6,667	$	6,670	3.04	%	$	1,445	$	1,448
One through five years	2.04		134,449		132,594		2.98		8,369		8,370
After five through ten years	2.36		887,796		868,090		2.66		45,690		45,450
Over ten years	2.38		3,639,113		3,535,132		2.56		168,737		164,600
	2.38	%	$	4,668,025	$	4,542,486	2.60	%	$	224,241	$	219,868

Schedule of Realized Gains and Losses from Sale of Securities Classified as Available for Sale

The following is a summary of realized gains and losses from the sale of securities classified as available for sale. Gains or losses on securities sold are recorded on the trade date, using the specific identification method.

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Realized gains	$	9		$	—
Realized losses	(68		)	—
	$	(59	)	$	—

Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets

The Company accounts for the following securities at cost less impairment plus or minus any observable price changes, which approximates fair value, with the exception of CRA and Community Development Investment Funds, which are recorded at fair value. Other Equity Securities, which are presented in “other assets” on the consolidated balance sheets, are as follows:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Federal Home Loan Bank (FHLB) stock	$	90,561	$	95,171
Federal Reserve Bank (FRB) stock	79,191		79,191
CRA and Community Development Investment Funds	9,801		—
Other investments	9,705		3,008
	$	189,258	$	177,370

XML

Allowance for Credit Losses and Credit Quality (Tables)

3 Months Ended

Mar. 31, 2018

Receivables [Abstract]

Schedule of Allowance for Loan Losses for Covered and Non-Covered Loan Portfolios

A summary of changes in the allowance for credit losses for the three months ended March 31 is as follows:

(Dollars in thousands)	2018			2017
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	$	140,891		$	144,719
Provision for loan and lease losses	7,986			6,154
Transfer of balance to OREO and other	(47		)	73
Charge-offs	(9,116		)	(7,291		)
Recoveries	4,813			1,235
Allowance for loan and lease losses at end of period	$	144,527		$	144,890
Reserve for unfunded commitments at beginning of period	$	13,208		$	11,241
Provision for unfunded lending commitments	224			419
Reserve for unfunded commitments at end of period	$	13,432		$	11,660
Allowance for credit losses at end of period	$	157,959		$	156,550

A summary of changes in the allowance for credit losses, by loan portfolio type, for the three months ended March 31 is as follows:

	2018
(Dollars in thousands)	Commercial Real Estate			Commercial and Industrial			Residential Mortgage			Consumer			Total
Allowance for loan and lease losses at beginning of period	$	54,201		$	53,916		$	9,117		$	23,657		$	140,891
Provision for (Reversal of) loan and lease losses	6,377			294			(686		)	2,001			7,986
Transfer of balance to OREO and other	(47		)	—			—			—			(47		)
Charge-offs	(114		)	(5,378		)	(105		)	(3,519		)	(9,116		)
Recoveries	191			3,698			22			902			4,813
Allowance for loan and lease losses at end of period	$	60,608		$	52,530		$	8,348		$	23,041		$	144,527
Reserve for unfunded commitments at beginning of period	$	4,531		$	5,309		$	555		$	2,813		$	13,208
Provision for (Reversal of) unfunded commitments	1,476			(1,004		)	(15		)	(233		)	224
Reserve for unfunded commitments at end of period	$	6,007		$	4,305		$	540		$	2,580		$	13,432
Allowance on loans individually evaluated for impairment	$	2,506		$	14,040		$	178		$	2,974		$	19,698
Allowance on loans collectively evaluated for impairment	35,871			36,208			2,073			16,544			90,696
Allowance on loans acquired with deteriorated credit quality	22,231			2,282			6,097			3,523			34,133
Loans and leases, net of unearned income:
Balance at end of period	$	9,248,951		$	5,325,682		$	3,971,067		$	3,160,390		$	21,706,090
Balance at end of period individually evaluated for impairment	78,489			78,725			6,041			33,277			196,532
Balance at end of period collectively evaluated for impairment	8,946,138			5,211,736			3,826,721			3,043,085			21,027,680
Balance at end of period acquired with deteriorated credit quality	224,324			35,221			138,305			84,028			481,878

	2017
(Dollars in thousands)	Commercial Real Estate			Commercial and Industrial			Residential Mortgage			Consumer			Total
Allowance for loan losses at beginning of period	$	49,231		$	60,939		$	11,249		$	23,300		$	144,719
Provision for (Reversal of) loan and lease losses	1,786			2,557			(1,060		)	2,871			6,154
Transfer of balance to OREO and other	377			(350		)	2			44			73
Charge-offs	(95		)	(3,762		)	(22		)	(3,412		)	(7,291		)
Recoveries	196			84			43			912			1,235
Allowance for loan losses at end of period	$	51,495		$	59,468		$	10,212		$	23,715		$	144,890
Reserve for unfunded commitments at beginning of period	$	3,207		$	4,537		$	657		$	2,840		$	11,241
Provision for (Reversal of) unfunded commitments	1,379			(885		)	(49		)	(26		)	419
Reserve for unfunded commitments at end of period	$	4,586		$	3,652		$	608		$	2,814		$	11,660
Allowance on loans individually evaluated for impairment	$	1,916		$	25,056		$	113		$	1,724		$	28,809
Allowance on loans collectively evaluated for impairment	26,872			32,383			3,907			17,764			80,926
Allowance on loans acquired with deteriorated credit quality	22,707			2,029			6,192			4,227			35,155
Loans, net of unearned income:
Balance at end of period	$	7,021,341		$	3,975,734		$	1,296,358		$	2,838,769		$	15,132,202
Balance at end of period individually evaluated for impairment	74,351			164,405			5,048			25,308			269,112
Balance at end of period collectively evaluated for impairment	6,687,651			3,778,775			1,176,017			2,723,308			14,365,751
Balance at end of period acquired with deteriorated credit quality	259,339			32,554			115,293			90,153			497,339

Investment in Legacy and Acquired Loans by Credit Quality Indicator

The Company’s investment in loans by credit quality indicator is presented in the following tables. Asset risk classifications for commercial loans and leases reflect the classification as of March 31, 2018 and December 31, 2017. Credit quality information in the tables below includes total loans acquired (including acquired impaired loans) at the net loan balance, after the application of premiums/discounts, at March 31, 2018 and December 31, 2017. Loan premiums/discounts represent the adjustment of acquired loans to fair value at the acquisition date, as adjusted for income accretion and changes in cash flow estimates in subsequent periods. Loan premiums/discounts include preliminary discounts recorded on acquired Sabadell United and Gibraltar loans, which are subject to change upon receipt of final fair value estimates during the measurement period.

Loan delinquency is the primary credit quality indicator that the Company utilizes to monitor consumer asset quality.

	March 31, 2018										December 31, 2017
(Dollars in thousands)	Pass		Special Mention		Sub- standard		Doubtful		Total		Pass		Special Mention		Sub- standard		Doubtful		Loss		Total
Commercial real estate - construction	$	1,153,604	$	16,399	$	29,610	$	12	$	1,199,625	$	1,189,490	$	20,351	$	30,541	$	14	$	—	$	1,240,396
Commercial real estate - owner-occupied	2,464,072		83,356		56,409		8,407		2,612,244		2,388,715		82,114		56,590		2,466		—		2,529,885
Commercial real estate- non-owner-occupied	5,335,816		45,905		51,089		4,272		5,437,082		5,104,074		19,311		42,702		1,744		118		5,167,949
Commercial and industrial	5,124,676		55,041		107,126		38,839		5,325,682		4,882,554		88,149		128,961		35,403		—		5,135,067
Total	$	14,078,168	$	200,701	$	244,234	$	51,530	$	14,574,633	$	13,564,833	$	209,925	$	258,794	$	39,627	$	118	$	14,073,297

	March 31, 2018						December 31, 2017
(Dollars in thousands)	Current		30+ Days Past Due		Total		Current		30+ Days Past Due		Total
Residential mortgage	$	3,859,751	$	111,316	$	3,971,067	$	2,962,043	$	94,309	$	3,056,352
Consumer - home equity	2,376,171		45,015		2,421,186		2,250,205		42,070		2,292,275
Consumer - indirect automobile	48,587		2,084		50,671		59,836		2,857		62,693
Consumer - credit card	92,497		764		93,261		95,263		1,105		96,368
Consumer - other	589,098		6,174		595,272		490,399		6,797		497,196
Total	$	6,966,104	$	165,353	$	7,131,457	$	5,857,746	$	147,138	$	6,004,884

Schedule of Investment in Legacy Impaired Loans

Information on the Company’s investment in impaired loans, which include all TDRs and all other non-accrual loans evaluated or measured individually for impairment for purposes of determining the ALLL, is presented in the following tables as of and for the periods indicated.

	March 31, 2018							December 31, 2017
	Unpaid Principal Balance		Recorded Investment		Related Allowance			Unpaid Principal Balance		Recorded Investment		Related Allowance
(Dollars in thousands)
With no related allowance recorded:
Commercial real estate- construction	$	11,153	$	11,153	$	—		$	13,763	$	13,013	$	—
Commercial real estate- owner-occupied	43,562		36,042		—			50,867		44,482		—
Commercial real estate- non-owner-occupied	10,575		10,449		—			15,370		14,975		—
Commercial and industrial	45,720		36,829		—			103,013		70,254		—
Residential mortgage	1,083		1,083		—			2,004		2,001		—
Consumer - home equity	31		31		—			5,906		5,634		—
Consumer -other	—		—		—			75		75		—
With an allowance recorded:
Commercial real estate- construction	236		154		(18		)	238		156		(19		)
Commercial real estate- owner-occupied	17,536		17,419		(1,860		)	13,314		13,287		(949		)
Commercial real estate- non-owner-occupied	3,399		3,272		(628		)	6,051		5,872		(620		)
Commercial and industrial	46,705		41,896		(14,040		)	35,306		32,162		(12,736		)
Residential mortgage	5,357		4,958		(178		)	5,179		4,748		(172		)
Consumer - home equity	28,917		28,187		(2,435		)	27,189		26,575		(2,358		)
Consumer - indirect automobile	1,004		656		(75		)	1,034		679		(79		)
Consumer - other	4,493		4,403		(464		)	4,320		4,214		(419		)
Total	$	219,771	$	196,532	$	(19,698	)	$	283,629	$	238,127	$	(17,352	)
Total commercial loans and leases	$	178,886	$	157,214	$	(16,546	)	$	237,922	$	194,201	$	(14,324	)
Total mortgage loans	6,440		6,041		(178		)	7,183		6,749		(172		)
Total consumer loans	34,445		33,277		(2,974		)	38,524		37,177		(2,856		)

	Three Months Ended March 31, 2018				Three Months Ended March 31, 2017
	Average Recorded Investment		Interest Income Recognized		Average Recorded Investment		Interest Income Recognized
(Dollars in thousands)
With no related allowance recorded:
Commercial real estate- construction	$	10,470	$	144	$	—	$	—
Commercial real estate- owner-occupied	36,277		334		37,197		339
Commercial real estate- non-owner-occupied	10,557		98		5,988		17
Commercial and industrial	27,832		385		90,664		448
Residential mortgage	1,090		12		735		5
Consumer - home equity	32		—		4,158		40
With an allowance recorded:
Commercial real estate- construction	153		1		1,984		1
Commercial real estate- owner-occupied	17,608		112		20,980		79
Commercial real estate- non-owner-occupied	3,302		10		8,587		94
Commercial and industrial	44,056		196		78,695		220
Residential mortgage	4,974		44		4,335		42
Consumer - home equity	28,203		292		16,713		179
Consumer - indirect automobile	717		5		767		7
Consumer - other	4,483		62		3,328		52
Total	$	189,754	$	1,695	$	274,131	$	1,523
Total commercial loans and leases	$	150,255	$	1,280	$	244,095	$	1,198
Total mortgage loans	6,064		56		5,070		47
Total consumer loans	33,435		359		24,966		278

XML

Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Carrying Amount of Goodwill

Changes to the carrying amount of goodwill by reporting unit for the three months ended March 31, 2018, and the year ended December 31, 2017 are provided in the following table.

(Dollars in thousands)	IBERIABANK		Mortgage		LTC		Total
Balance, December 31, 2016	$	698,513	$	23,178	$	5,165	$	726,856
Goodwill acquired during the year (preliminary allocation)	462,046		—		—		462,046
Balance, December 31, 2017	$	1,160,559	$	23,178	$	5,165	$	1,188,902
Goodwill acquired during the year (preliminary allocation) and adjustments	43,887		—		3,380		47,267
Balance, March 31, 2018	$	1,204,446	$	23,178	$	8,545	$	1,236,169

Schedule of Mortgage Servicing Rights

Mortgage Servicing Rights

Mortgage servicing rights are recorded at the lower of cost or market value in “other intangible assets” on the Company's consolidated balance sheets and amortized over the remaining servicing life of the loans, with consideration given to prepayment assumptions. Mortgage servicing rights had the following carrying values as of the periods indicated:

	March 31, 2018							December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
(Dollars in thousands)
Mortgage servicing rights	$	10,030	$	(4,128	)	$	5,902	$	9,588	$	(3,931	)	$	5,657

Schedule of Definite-Lived Intangible Assets

Definite-lived intangible assets had the following carrying values included in “other intangible assets” on the Company’s consolidated balance sheets as of the periods indicated:

	March 31, 2018							December 31, 2017
(Dollars in thousands)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Core deposit intangible assets	$	136,183	$	(46,736	)	$	89,447	$	127,957	$	(51,971	)	$	75,986
Customer relationship intangible asset	1,385		(1,262		)	123		1,143		(996		)	147
Non-compete agreement	206		(36		)	170		63		(39		)	24
Total	$	137,774	$	(48,034	)	$	89,740	$	129,163	$	(53,006	)	$	76,157

XML

Derivative Instruments and Other Hedging Activities (Tables)

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Outstanding Derivative Instruments

Information pertaining to outstanding derivative instruments is as follows:

	Balance Sheet Location	Derivative Assets - Fair Value				Balance Sheet Location	Derivative Liabilities - Fair Value
(Dollars in thousands)		March 31, 2018		December 31, 2017			March 31, 2018		December 31, 2017
Derivatives designated as hedging instruments under ASC Topic 815:
Interest rate contracts	Other assets	$	—	$	—	Other liabilities	$	—	$	—
Total derivatives designated as hedging instruments under ASC Topic 815		$	—	$	—		$	—	$	—
Derivatives not designated as hedging instruments under ASC Topic 815:
Interest rate contracts	Other assets	$	5,827	$	20,446	Other liabilities	$	25,771	$	16,191
Foreign exchange contracts	Other assets	2		7		Other liabilities	2		7
Forward sales contracts	Other assets	2,851		136		Other liabilities	703		279
Written and purchased options	Other assets	8,383		10,654		Other liabilities	5,667		8,656
Other contracts	Other assets	9		22		Other liabilities	11		21
Total derivatives not designated as hedging instruments under ASC Topic 815		$	17,072	$	31,265		$	32,154	$	25,154
Total		$	17,072	$	31,265		$	32,154	$	25,154

	Derivative Assets - Notional Amount				Derivative Liabilities - Notional Amount
(Dollars in thousands)	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
Derivatives designated as hedging instruments under ASC Topic 815:
Interest rate contracts	$	108,500	$	—	$	—	$	108,500
Total derivatives designated as hedging instruments under ASC Topic 815	$	108,500	$	—	$	—	$	108,500
Derivatives not designated as hedging instruments under ASC Topic 815:
Interest rate contracts	$	1,356,990	$	1,218,464	$	1,276,990	$	1,218,464
Foreign exchange contracts	628		268		628		268
Forward sales contracts	96,810		82,347		215,918		142,578
Written and purchased options	339,852		278,638		164,341		165,198
Other contracts	29,676		29,755		71,889		86,744
Total derivatives not designated as hedging instruments under ASC Topic 815	$	1,823,956	$	1,609,472	$	1,729,766	$	1,613,252
Total	$	1,932,456	$	1,609,472	$	1,729,766	$	1,721,752

Offsetting Assets

The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset.

	March 31, 2018
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet					Net
(Dollars in thousands)			Derivatives			Collateral  (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	5,827	$	(548	)	$	—	$	5,279
Written and purchased options	5,656		—			—		5,656
Total derivative assets subject to master netting arrangements	$	11,483	$	(548	)	$	—	$	10,935
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—	$	—
Interest rate contracts not designated as hedging instruments	25,771		(548		)	—		25,223
Written and purchased options	5,587		—			—		5,587
Total derivative liabilities subject to master netting arrangements	$	31,358	$	(548	)	$	—	$	30,810

^{(1) Consists of cash collateral recorded at cost, which approximates fair value, and investment securities.} 

	December 31, 2017
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet						Net
(Dollars in thousands)			Derivatives			Collateral (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	20,446	$	(12,469	)	$	—		$	7,977
Written and purchased options	8,610		—			—			8,610
Total derivative assets subject to master netting arrangements	$	29,056	$	(12,469	)	$	—		$	16,587
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—		$	—
Interest rate contracts not designated as hedging instruments	16,191		(12,469		)	(552		)	3,170
Total derivative liabilities subject to master netting arrangements	$	16,191	$	(12,469	)	$	(552	)	$	3,170

Offsetting Liabilities

The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset.

	March 31, 2018
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet					Net
(Dollars in thousands)			Derivatives			Collateral  (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	5,827	$	(548	)	$	—	$	5,279
Written and purchased options	5,656		—			—		5,656
Total derivative assets subject to master netting arrangements	$	11,483	$	(548	)	$	—	$	10,935
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—	$	—
Interest rate contracts not designated as hedging instruments	25,771		(548		)	—		25,223
Written and purchased options	5,587		—			—		5,587
Total derivative liabilities subject to master netting arrangements	$	31,358	$	(548	)	$	—	$	30,810

^{(1) Consists of cash collateral recorded at cost, which approximates fair value, and investment securities.} 

	December 31, 2017
	Gross Amounts Presented in the Balance Sheet		Gross Amounts Not Offset in the Balance Sheet						Net
(Dollars in thousands)			Derivatives			Collateral (1)
Derivatives subject to master netting arrangements
Derivative assets
Interest rate contracts not designated as hedging instruments	$	20,446	$	(12,469	)	$	—		$	7,977
Written and purchased options	8,610		—			—			8,610
Total derivative assets subject to master netting arrangements	$	29,056	$	(12,469	)	$	—		$	16,587
Derivative liabilities
Interest rate contracts designated as hedging instruments	$	—	$	—		$	—		$	—
Interest rate contracts not designated as hedging instruments	16,191		(12,469		)	(552		)	3,170
Total derivative liabilities subject to master netting arrangements	$	16,191	$	(12,469	)	$	(552	)	$	3,170

Effect of Derivatives on the Consolidated Financial Statements

At March 31, 2018 and 2017, and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements is as follows:

													Location of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	Amount of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)
			Amount of Gain (Loss) Recognized in OCI, net of taxes			Location of Gain (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain (Loss) Reclassified from Accumulated OCI into Income, net of taxes
(Dollars in thousands)
			For the Three Months Ended March 31
Derivatives in ASC Topic 815 Cash Flow Hedging Relationships		2018		2017			2018			2017				2018		2017
	Interest rate contracts	$	2,549	$	73	Interest expense	$	(116	)	$	(45	)	Interest expense	$	—	$	—
Total		$	2,549	$	73		$	(116	)	$	(45	)		$	—	$	—

Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, is as follows:

	Location of Gain (Loss) Recognized in  Income on Derivatives	Amount of Gain (Loss) Recognized in Income on Derivatives
		For the Three Months Ended March 31
(Dollars in thousands)		2018			2017
Interest rate contracts (1)	Other income	$	1,049		$	1,117
Foreign exchange contracts	Other income	5			7
Forward sales contracts	Mortgage income	3,387			(360		)
Written and purchased options	Mortgage income	648			655
Other contracts	Other income	(3		)	4
Total		$	5,086		$	1,423

XML

Income Taxes Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The following table presents the provision for income taxes and the effective tax rates for the three months ended March 31, 2018 and 2017:

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Income before income tax expense	$	81,173		$	72,992
Income tax expense	17,552			22,519
Effective tax rate	21.6		%	30.9		%

XML

Shareholders' Equity, Capital Ratios and Other Regulatory Matters (Tables)

3 Months Ended

Mar. 31, 2018

Banking and Thrift [Abstract]

Schedule of Preferred Stock

The following table presents a summary of the Company's non-cumulative perpetual preferred stock:

							March 31, 2018		December 31, 2017
	Issuance Date	Earliest Redemption Date	Annual Dividend Rate		Liquidation Amount		Carrying Amount		Carrying Amount
(Dollars in thousands)
Series B Preferred Stock	8/5/2015	8/1/2025	6.625	%	$	80,000	$	76,812	$	76,812
Series C Preferred Stock	5/9/2016	5/1/2026	6.600	%	57,500		55,285		55,285
					$	137,500	$	132,097	$	132,097

Actual Capital Amounts and Ratios

The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2018 and December 31, 2017 are presented in the following tables.

(Dollars in thousands)	March 31, 2018
	Minimum				Well-Capitalized		Actual
	Amount		Ratio		Amount	Ratio	Amount		Ratio
Tier 1 Leverage
Consolidated	$	1,076,933	4.00	%	N/A	N/A	$	2,685,315	9.97	%
IBERIABANK	1,074,579		4.00		1,343,223	5.00	2,640,916		9.83
Common Equity Tier 1 (CET1) (1)
Consolidated	$	1,067,284	4.50	%	N/A	N/A	$	2,553,218	10.77	%
IBERIABANK	1,065,059		4.50		1,538,418	6.50	2,640,916		11.16
Tier 1 Risk-Based Capital (1)
Consolidated	$	1,423,046	6.00	%	N/A	N/A	$	2,685,315	11.32	%
IBERIABANK	1,420,078		6.00		1,893,437	8.00	2,640,916		11.16
Total Risk-Based Capital (1)
Consolidated	$	1,897,394	8.00	%	N/A	N/A	$	2,959,774	12.48	%
IBERIABANK	1,893,437		8.00		2,366,797	10.00	2,798,875		11.83

	December 31, 2017
	Minimum				Well-Capitalized		Actual
	Amount		Ratio		Amount	Ratio	Amount		Ratio
Tier 1 Leverage
Consolidated	$	1,073,381	4.00	%	N/A	N/A	$	2,509,496	9.35	%
IBERIABANK	1,070,789		4.00		1,338,487	5.00	2,437,275		9.10
Common Equity Tier 1 (CET1) (1)
Consolidated	$	1,011,732	4.50	%	N/A	N/A	$	2,377,398	10.57	%
IBERIABANK	1,009,553		4.50		1,458,243	6.50	2,437,275		10.86
Tier 1 Risk-Based Capital (1)
Consolidated	$	1,348,977	6.00	%	N/A	N/A	$	2,509,496	11.16	%
IBERIABANK	1,346,070		6.00		1,794,760	8.00	2,437,275		10.86
Total Risk-Based Capital (1)
Consolidated	$	1,798,635	8.00	%	N/A	N/A	$	2,780,095	12.37	%
IBERIABANK	1,794,760		8.00		2,243,450	10.00	2,591,374		11.55

⁽¹⁾ Minimum capital ratios are subject to a capital conservation buffer. In order to avoid limitations on distributions, including dividend payments, and certain discretionary bonus payments to executive officers, an institution must hold a capital conservation buffer above its minimum risk-based capital requirements. This capital conservation buffer is calculated as the lowest of the differences between the actual CET1 ratio, Tier 1 Risk-Based Capital Ratio, and Total Risk-Based Capital ratio and the corresponding minimum ratios. At March 31, 2018, the required minimum capital conservation buffer was 1.875%, and will increase by 0.625% and be fully phased-in on January 1, 2019 at 2.50%. At March 31, 2018, the capital conservation buffers of the Company and IBERIABANK were 4.48% and 3.83%, respectively.

XML

Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Schedule of Calculation of Basic and Diluted Earnings Per Share

The following table presents the calculation of basic and diluted earnings per share for the periods indicated.

	Three Months Ended March 31,
(In thousands, except per share data)	2018			2017
Earnings per common share - basic:
Net income	$	63,621		$	50,473
Less: Preferred stock dividends	3,598			3,599
Less: Dividends and undistributed earnings allocated to unvested restricted shares	639			346
Net income allocated to common shareholders - basic	$	59,384		$	46,528
Weighted average common shares outstanding	53,616			46,123
Earnings per common share - basic	1.11			1.01
Earnings per common share - diluted:
Net income allocated to common shareholders - basic	$	59,384		$	46,528
Adjustment for undistributed earnings allocated to unvested restricted shares	(18		)	(37		)
Net income allocated to common shareholders - diluted	$	59,366		$	46,491
Weighted average common shares outstanding	53,616			46,123
Dilutive potential common shares	351			373
Weighted average common shares outstanding - diluted	53,967			46,496
Earnings per common share - diluted	$	1.10		$	1.00

XML

Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation Arrangements by Share-based Payment Award

The following table represents unvested restricted stock award and restricted share unit activity for the following periods:

	For the Three Months Ended March 31,
	2018		2017
Number of shares at beginning of period	738,187		543,258
Granted	199,958		146,175
Forfeited	(43,405	)	(4,105	)
Vested	(115,877	)	(157,753	)
Number of shares at end of period	778,863		527,575

The following table represents phantom stock award activity during the periods indicated.

(Dollars in thousands)	Number of share equivalents (1)		Value of share equivalents (2)
Balance, December 31, 2016	472,830		$	39,600
Granted	96,897		7,665
Forfeited share equivalents	(5,330	)	422
Vested share equivalents	(143,643	)	12,024
Balance, March 31, 2017	420,754		$	33,282
Balance, December 31, 2017	393,844		$	30,523
Granted	129,234		10,080
Forfeited share equivalents	(24,460	)	1,908
Vested share equivalents	(121,758	)	10,187
Balance, March 31, 2018	376,860		$	29,395

⁽¹⁾  Number of share equivalents includes all reinvested dividend equivalents for the periods indicated.

⁽²⁾  Except for share equivalents at the beginning of each period, which are based on the value at that time, and vested share payments, which are based on the cash paid at the time of vesting, the value of share equivalents is calculated based on the market price of the Company’s stock at the end of the respective periods. The market price of the Company’s stock was $78.00 and $79.10 on March 31, 2018, and 2017, respectively.

The following table represents the activity related to stock options during the periods indicated:

	Number of Shares		Weighted Average Exercise Price
Outstanding options, December 31, 2016	721,538		$	55.38
Granted	70,433		85.52
Exercised	(24,457	)	53.85
Forfeited or expired	(12,539	)	75.77
Outstanding options, March 31, 2017	754,975		$	57.90
Exercisable options, March 31, 2017	509,347		$	55.78
Outstanding options, December 31, 2017	686,366		$	58.24
Granted	92,162		82.20
Exercised	(21,212	)	52.10
Forfeited or expired	(14,513	)	65.27
Outstanding options, March 31, 2018	742,803		$	61.25
Exercisable options, March 31, 2018	519,496		$	56.53

Schedule of Valuation Assumptions

The following weighted-average assumptions were used for option awards issued during the following periods:

	For the Three Months Ended March 31,
	2018			2017
Expected dividends	1.8		%	1.7		%
Expected volatility	24.3		%	24.9		%
Risk-free interest rate	2.7		%	2.1		%
Expected term (in years)	5.7			5.6
Weighted-average grant-date fair value	$	18.36		$	18.75

Schedule of Allocation for Share-based Compensation Expense

The following table represents the compensation expense that was included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to restricted stock awards and restricted share units for the periods indicated:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to restricted stock awards and restricted share units	$	4,422	$	3,277
Income tax benefit related to restricted stock awards and restricted share units	929		1,147

The following table represents the compensation expense that is included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to stock options for the following periods:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to stock options	$	312	$	444
Income tax benefit related to stock options	23		68

The following table indicates compensation expense recorded for phantom stock based on the number of share equivalents vested at March 31 of the periods indicated and the current market price of the Company’s stock at that time:

	For the Three Months Ended March 31,
(Dollars in thousands)	2018		2017
Compensation expense related to phantom stock	$	2,996	$	3,053

XML

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Financial Asset and Liabilities Measured at Fair Value on Recurring Basis

The Company has segregated all financial assets and liabilities that are measured at fair value on a recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to estimate the fair value at the measurement date in the tables below. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2017, for a description of how fair value measurements are determined.

	March 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Securities available for sale	$	—	$	4,542,486	$	—	$	4,542,486
CRA and Community Development Investment Funds	—		9,801		—		9,801
Mortgage loans held for sale	—		110,348		—		110,348
Derivative instruments	—		17,072		—		17,072
Total	$	—	$	4,679,707	$	—	$	4,679,707
Liabilities
Derivative instruments	$	—	$	32,154	$	—	$	32,154
Total	$	—	$	32,154	$	—	$	32,154
	December 31, 2017
	Level 1		Level 2		Level 3		Total
Assets
Securities available for sale	$	—	$	4,590,062	$	—	$	4,590,062
Mortgage loans held for sale	—		134,916		—		134,916
Derivative instruments	—		31,265		—		31,265
Total	$	—	$	4,756,243	$	—	$	4,756,243
Liabilities
Derivative instruments	$	—	$	25,154	$	—	$	25,154
Total	$	—	$	25,154	$	—	$	25,154

Financial Asset and Liabilities Measured at Fair Value on Nonrecurring Basis

The Company has segregated all assets and liabilities that are measured at fair value on a non-recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date in the tables below.

	March 31, 2018
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Loans	$	—	$	—	$	85,269	$	85,269
OREO, net	—		—		2,234		2,234
Total	$	—	$	—	$	87,503	$	87,503
	December 31, 2017
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets
Loans	$	—	$	—	$	71,210	$	71,210
OREO, net	—		—		3,029		3,029
Total	$	—	$	—	$	74,239	$	74,239

Summary of Difference Between the Aggregate Fair Value and the Aggregate Unpaid Principal Balance for Mortgage Loans Held for Sale

The following table summarizes the difference between the aggregate fair value and the aggregate unpaid principal balance for mortgage loans held for sale measured at fair value:

	March 31, 2018						December 31, 2017
(Dollars in thousands)	Aggregate Fair Value		Aggregate Unpaid Principal		Aggregate Fair Value Less Unpaid Principal		Aggregate Fair Value		Aggregate Unpaid Principal		Aggregate Fair Value Less Unpaid Principal
Mortgage loans held for sale, at fair value	$	110,348	$	107,849	$	2,499	$	134,916	$	131,276	$	3,640

XML

Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Estimated Fair Values and Carrying Amounts of Financial Instruments

The carrying amount and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are included in the tables below. See Note 1, Summary of Significant Accounting Policies, in the 2017 Annual Report on Form 10-K for the year ended December 31, 2017 for a description of how fair value measurements are determined, except for loans, amended upon implementation of ASU 2016-01, Financial Statements - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. See Note 2, Recent Accounting Pronouncements, in this Report for a description of how the fair value measurement is determined for loans beginning January 1, 2018.

		March 31, 2018
(Dollars in thousands)		Carrying  Amount		Fair Value		Level 1		Level 2		Level 3
Measurement Category
Fair Value
	Financial Assets
	Securities available for sale	$	4,542,486	$	4,542,486	$	—	$	4,542,486	$	—
	CRA and Community Development Investment Funds	9,801		9,801		—		9,801		—
	Mortgage loans held for sale	110,348		110,348		—		110,348		—
	Derivative instruments	17,072		17,072		—		17,072		—
	Financial Liabilities
	Derivative instruments	32,154		32,154		—		32,154		—
Amortized Cost
	Financial Assets
	Cash and cash equivalents	$	564,092	$	564,092	$	564,092	$	—	$	—
	Securities held to maturity	224,241		219,868		—		219,868		—
	Loans and leases, net of unearned income and allowance for loan and lease losses	21,561,563		21,495,639		—		—		21,495,639
	Financial Liabilities
	Deposits	22,971,192		22,970,554		—		22,970,554		—
	Short-term borrowings	900,496		900,496		525,496		375,000		—
	Long-term debt	1,449,302		1,429,335		—		—		1,429,335

		December 31, 2017
(Dollars in thousands)		Carrying Amount		Fair Value		Level 1		Level 2		Level 3
Measurement Category
Fair Value
	Financial Assets
	Securities available for sale	$	4,590,062	$	4,590,062	$	—	$	4,590,062	$	—
	Mortgage loans held for sale	134,916		134,916		—		134,916		—
	Derivative instruments	31,265		31,265		—		31,265		—
	Financial Liabilities
	Derivative instruments	25,154		25,154		—		25,154		—
Amortized Cost
	Financial Assets
	Cash and cash equivalents	$	625,724	$	625,724	$	625,724	$	—	$	—
	Securities held to maturity	227,318		227,964		—		227,964		—
	Loans and leases, net of unearned income and allowance for loan and lease losses	19,937,290		19,826,857		—		—		19,826,857
	Financial Liabilities
	Deposits	21,466,717		21,460,782		—		21,460,782		—
	Short-term borrowings	991,297		991,297		516,297		475,000		—
	Long-term debt	1,495,835		1,476,899		—		—		1,476,899

XML

Business Segments (Tables)

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Schedule of Segment Reporting Information

The following tables present certain information regarding our operations by reportable segment, including a reconciliation of segment results to reported consolidated results for the periods presented. Reconciling items between segment results and reported results include:

• Elimination of interest income and interest expense representing interest earned by IBERIABANK on interest-bearing checking accounts held by related companies, as well as the elimination of the related deposit balances at the IBERIABANK segment;

• Elimination of investment in subsidiary balances on certain operating segments included in total and average segment assets; and

• Elimination of intercompany due to and due from balances on certain operating segments that are included in total and average segment assets.

	Three Months Ended March 31, 2018
(Dollars in thousands)	IBERIABANK			Mortgage			LTC			Consolidated
Interest and dividend income	$	268,775		$	1,767		$	1		$	270,543
Interest expense	37,654			—			—			37,654
Net interest income	231,121			1,767			1			232,889
Provision for/(reversal of) loan and lease losses	7,991			(5		)	—			7,986
Mortgage income	—			9,595			—			9,595
Title revenue	—			—			5,027			5,027
Other non-interest income	29,906			38			—			29,944
Allocated expenses	(1,479		)	1,166			313			—
Non-interest expense	171,816			11,916			4,564			188,296
Income/(loss) before income tax expense	82,699			(1,677		)	151			81,173
Income tax expense/(benefit)	18,540			(410		)	(578		)	17,552
Net income/(loss)	$	64,159		$	(1,267	)	$	729		$	63,621
Total loans, leases, and loans held for sale, net of unearned income	$	21,652,223		$	164,215		$	—		$	21,816,438
Total assets	29,243,983			205,497			23,157			29,472,637
Total deposits	22,959,061			12,131			—			22,971,192
Average assets	27,924,587			185,742			21,890			28,132,219

	Three Months Ended March 31, 2017
(Dollars in thousands)	IBERIABANK			Mortgage			LTC			Consolidated
Interest and dividend income	$	190,823		$	1,709		$	1		$	192,533
Interest expense	19,715			—			—			19,715
Net interest income	171,108			1,709			1			172,818
Provision for/(reversal of) loan and lease losses	6,158			(4		)	—			6,154
Mortgage income	—			14,115			—			14,115
Title revenue	—			—			4,741			4,741
Other non-interest income	26,284			(10		)	(6		)	26,268
Allocated expenses	(2,174		)	1,656			518			—
Non-interest expense	119,429			15,167			4,200			138,796
Income/(loss) before income tax expense	73,979			(1,005		)	18			72,992
Income tax expense/(benefit)	22,829			(322		)	12			22,519
Net income/(loss)	$	51,150		$	(683	)	$	6		$	50,473
Total loans, leases, and loans held for sale, net of unearned income	$	15,072,661		$	181,874		$	—		$	15,254,535
Total assets	21,774,586			209,911			23,982			22,008,479
Total deposits	17,306,328			5,937			—			17,312,265
Average assets	21,550,930			286,694			23,877			21,861,501

XML

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Summary of Financial Instruments Outstanding

At March 31, 2018 and December 31, 2017, respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk:

(Dollars in thousands)	March 31, 2018		December 31, 2017
Commitments to grant loans	$	319,318	$	342,305
Unfunded commitments under lines of credit	6,340,135		6,060,034
Commercial and standby letters of credit	211,070		210,002
Reserve for unfunded lending commitments	13,432		13,208

XML

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	[1]		$ (345)
Equity Securities, FV-NI		$ 9,801		$ 0
ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 2,200

[1] Cumulative-effect adjustment to beginning retained earnings for fair value adjustments related to the reclassification of certain equity investments in accordance with ASU 2016-01, adopted as of January 1, 2018.

XML

Loans - Schedule of Non-Covered Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 21,706,090	$ 20,078,181
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	14,574,633	14,073,297
Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	1,199,625	1,240,396
Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,612,244	2,529,885
Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	5,437,082	5,167,949
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	5,325,682	5,135,067
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	3,971,067	3,056,352
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	3,160,390	2,948,532
Consumer and Other Loans | Home Equity
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,421,186	2,292,275
Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	50,671	62,693
Consumer and Other Loans | Other
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 595,272	$ 497,196

XML

Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 23, 2018	Dec. 31, 2017	Jul. 31, 2017
Accounts, Notes, Loans and Financing Receivable
Net deferred loan origination fees	$ 31,400			$ 29,300
Net discount	158,100			159,300
Deposit liabilities reclassified as loans receivable	7,300			7,400
Loans with carrying value pledged to secure public deposits and other borrowings	6,800,000			6,600,000
Loans acquired with no evidence of deteriorated credit quality	17,000			15,000
Acquired Loans
Accounts, Notes, Loans and Financing Receivable
Net discount	100,800			94,700
Sabadell United
Accounts, Notes, Loans and Financing Receivable
Loans acquired					$ 4,025,946
Covered loans acquired	150,000			158,600
Sabadell United | Non-US [Member]
Accounts, Notes, Loans and Financing Receivable
Covered loans acquired	336,100			$ 325,500
Gibraltar Private Bank & Trust Company [Member]
Accounts, Notes, Loans and Financing Receivable
Loans acquired	1,500,000		$ 1,465,319
Loans acquired with no evidence of deteriorated credit quality	1,455,085
Loans acquired with deteriorated credit quality	10,234
Troubled Debt Restructurings [Member]
Accounts, Notes, Loans and Financing Receivable
TDRs during period	27,200	$ 13,165
TDRs during period on accrual status	12,900	11,800
TDRs during period on non-accrual status	$ 14,300	$ 1,400

XML

Loans - Schedule of Aging of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable
Accruing	$ 86,581	$ 68,617
Non-accrual Loans	153,975	145,388
Acquired Impaired Loans	196,532	238,127
Total Loans	21,706,090	20,078,181
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	157,214	194,201
Total Loans	14,574,633	14,073,297
Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	971	727
Non-accrual Loans	2,634	2,635
Total Loans	1,199,625	1,240,396
Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	8,228	2,364
Non-accrual Loans	35,144	24,457
Total Loans	2,612,244	2,529,885
Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	16,584	9,378
Non-accrual Loans	9,378	6,811
Total Loans	5,437,082	5,167,949
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	11,434	11,660
Non-accrual Loans	66,637	77,823
Total Loans	5,325,682	5,135,067
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	6,041	6,749
Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Current	3,859,751	2,962,043
Accruing	29,521	23,536
Non-accrual Loans	19,932	17,387
Total Loans	3,971,067	3,056,352
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	33,277	37,177
Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Current	2,376,171	2,250,205
Accruing	15,051	14,640
Non-accrual Loans	16,383	12,365
Total Loans	2,421,186	2,292,275
Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Current	48,587	59,836
Accruing	1,341	1,973
Non-accrual Loans	743	884
Total Loans	50,671	62,693
Consumer and Other Loans | Consumer - Credit card
Accounts, Notes, Loans and Financing Receivable
Current	92,497	95,263
Accruing	261	514
Non-accrual Loans	503	590
Total Loans	93,261	96,368
Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Current	589,098	490,399
Accruing	3,190	3,825
Non-accrual Loans	2,621	2,436
Total Loans	595,272	497,196
Current or Less Than 30 days past due
Accounts, Notes, Loans and Financing Receivable
Current	20,983,656	19,382,621
Current or Less Than 30 days past due | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Current	1,157,115	1,197,766
Current or Less Than 30 days past due | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Current	2,474,611	2,398,487
Current or Less Than 30 days past due | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Current	5,319,962	5,066,084
Current or Less Than 30 days past due | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Current	5,212,390	5,014,438
Current or Less Than 30 days past due | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Current	3,783,309	2,877,048
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Current	2,309,222	2,186,554
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Current	48,581	59,830
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Credit card
Accounts, Notes, Loans and Financing Receivable
Current	92,497	95,264
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Current	585,969	487,150
30-59 days
Accounts, Notes, Loans and Financing Receivable
Accruing	61,956	36,818
30-59 days | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	842	269
30-59 days | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	4,767	1,631
30-59 days | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	7,269	2,086
30-59 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	7,755	5,788
30-59 days | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	25,640	10,083
30-59 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	11,860	11,675
30-59 days | Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Accruing	1,166	1,796
30-59 days | Consumer and Other Loans | Consumer - Credit card
Accounts, Notes, Loans and Financing Receivable
Accruing	173	140
30-59 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	2,484	3,350
60-89 days
Accounts, Notes, Loans and Financing Receivable
Accruing	16,337	24,899
60-89 days | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	129	0
60-89 days | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	3,461	659
60-89 days | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	2,526	6,405
60-89 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	3,406	5,726
60-89 days | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	2,655	8,136
60-89 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	3,191	2,947
60-89 days | Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Accruing	175	177
60-89 days | Consumer and Other Loans | Consumer - Credit card
Accounts, Notes, Loans and Financing Receivable
Accruing	88	374
60-89 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	706	475
Greater than 90 days
Accounts, Notes, Loans and Financing Receivable
Accruing	8,288	6,900
Greater than 90 days | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	0	458
Greater than 90 days | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	0	74
Greater than 90 days | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	6,789	887
Greater than 90 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	273	146
Greater than 90 days | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	1,226	5,317
Greater than 90 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	0	18
Greater than 90 days | Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Consumer and Other Loans | Consumer - Credit card
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Acquired Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	481,878	481,555
Acquired Loans | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	38,905	39,268
Acquired Loans | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	94,261	104,577
Acquired Loans | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	91,158	85,676
Acquired Loans | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	35,221	31,146
Acquired Loans | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	138,305	138,381
Acquired Loans | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	80,530	78,716
Acquired Loans | Consumer and Other Loans | Consumer - Indirect automobile
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	6	6
Acquired Loans | Consumer and Other Loans | Consumer - Credit card
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	0	0
Acquired Loans | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	$ 3,492	$ 3,785

XML

Loans - Schedule of Carrying Amount of Loans Acquired (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 23, 2018	Dec. 31, 2017	Jul. 31, 2017	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable
Expected losses and foregone interest	$ (157,959)				$ (156,550)
Loans acquired with no evidence of deteriorated credit quality	17,000		$ 15,000
Related allowance	(2,974)		(2,856)
Sabadell United
Accounts, Notes, Loans and Financing Receivable
Loans acquired				$ 4,025,946
Covered loans acquired	150,000		$ 158,600
Gibraltar Private Bank & Trust Company [Member]
Accounts, Notes, Loans and Financing Receivable
Loans acquired	1,500,000	$ 1,465,319
Contractually required principal and interest at acquisition	1,695,918
Expected losses and foregone interest	(19,952)
Cash flows expected to be collected at acquisition	1,675,966
Loans acquired with no evidence of deteriorated credit quality	1,455,085
Impaired Financing Receivable, with Related Allowance, Recorded Investment	43,779
Related allowance	(31,174)
Impaired Financing Receivable, Expected Cash Flow	12,605
Accretable yield	(2,371)
Loans acquired with deteriorated credit quality	$ 10,234

XML

Loans - Summary of Changes in Accretable Yields of Acquired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 152,623	$ 175,054
Additions	2,371	0
Transfers from non-accretable difference to accretable yield	(279)	2,071
Accretion	(13,154)	(14,596)
Changes in expected cash flows not affecting non-accretable differences	9,687	1,060
Balance at end of period	$ 151,248	$ 163,589

XML

Loans - Schedule of Modified TDRs (Detail) - Troubled Debt Restructurings [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Modifications
TDRs during period on accrual status	$ 12,900	$ 11,800
TDRs during period on non-accrual status	14,300	1,400
Extended maturities	5,619	7,199
Maturity and interest rate adjustment	108	3,224
Movement to or extension of interest-rate only payments	48	1,290
Interest rate adjustment	105	0
Financing Receivable Modifications Forbearance	12,886	1,220
Other concession(s)	8,434	232
TDRs during period	$ 27,200	$ 13,165

XML

Loans - Schedule of Subsequently Defaulted TDRs (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) SecurityLoan	Mar. 31, 2017 USD ($) SecurityLoan
Accounts, Notes, Loans and Financing Receivable
Threshold period for loans in default (in days)	30 days
Non-Covered TDRs | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	65	101
Pre-modification Outstanding Recorded Investment	$ 30,616	$ 13,238
Post-modification Outstanding Recorded Investment	$ 27,200	$ 13,165
Number of loans | SecurityLoan	122	162
Recorded investment	$ 24,673	$ 28,416
Non-Covered TDRs | Commercial Loans | Commercial real estate - Construction | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	1	0
Pre-modification Outstanding Recorded Investment	$ 1,950	$ 0
Post-modification Outstanding Recorded Investment	$ 1,049	$ 0
Number of loans | SecurityLoan	0	1
Recorded investment	$ 0	$ 117
Non-Covered TDRs | Commercial Loans | Commercial real estate - owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	2	3
Pre-modification Outstanding Recorded Investment	$ 10,691	$ 3,004
Post-modification Outstanding Recorded Investment	$ 9,324	$ 2,999
Number of loans | SecurityLoan	3	9
Recorded investment	$ 10,187	$ 14,732
Non-Covered TDRs | Commercial Loans | Commercial real estate - non-owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	9	7
Pre-modification Outstanding Recorded Investment	$ 1,089	$ 1,867
Post-modification Outstanding Recorded Investment	$ 1,091	$ 1,855
Number of loans | SecurityLoan	9	10
Recorded investment	$ 492	$ 5,041
Non-Covered TDRs | Commercial Loans | Commercial and industrial | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	18	15
Pre-modification Outstanding Recorded Investment	$ 14,429	$ 435
Post-modification Outstanding Recorded Investment	$ 13,314	$ 427
Number of loans | SecurityLoan	29	21
Recorded investment	$ 9,708	$ 4,186
Non-Covered TDRs | Residential Mortgage | Residential mortgage | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	0	4
Pre-modification Outstanding Recorded Investment	$ 0	$ 259
Post-modification Outstanding Recorded Investment	$ 0	$ 241
Number of loans | SecurityLoan	6	22
Recorded investment	$ 598	$ 1,793
Non-Covered TDRs | Consumer and Other Loans | Consumer - Home equity | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	14	37
Pre-modification Outstanding Recorded Investment	$ 1,809	$ 6,622
Post-modification Outstanding Recorded Investment	$ 1,795	$ 6,607
Number of loans | SecurityLoan	24	31
Recorded investment	$ 2,331	$ 1,337
Non-Covered TDRs | Consumer and Other Loans | Consumer - Indirect Automobile | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	11	13
Pre-modification Outstanding Recorded Investment	$ 137	$ 184
Post-modification Outstanding Recorded Investment	$ 119	$ 174
Number of loans | SecurityLoan	34	43
Recorded investment	$ 322	$ 517
Non-Covered TDRs | Consumer and Other Loans | Consumer - Other | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	10	22
Pre-modification Outstanding Recorded Investment	$ 511	$ 867
Post-modification Outstanding Recorded Investment	$ 508	$ 862
Number of loans | SecurityLoan	17	25
Recorded investment	$ 1,035	$ 693

XML

Acquisition Activity - Additional Information (Details)				3 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 23, 2018 USD ($) $ / shares shares	Jul. 31, 2017 USD ($) bank shares	Mar. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Increase in goodwill due to adjustments				$ 47,267,000
Amortization of intangible assets acquired				5,102,000		$ 1,770,000
Goodwill	$ 1,236,169,000			1,236,169,000	$ 1,236,169,000		$ 1,188,902,000	$ 726,856,000
Gibraltar Private Bank & Trust Company
Business Acquisition [Line Items]
Loans acquired	1,500,000,000	$ 1,465,319,000		1,500,000,000	1,500,000,000
Interest-bearing deposits acquired		1,064,803,000
Cash consideration	214,700,000	7,000
Increase in goodwill due to adjustments	42,500,000
Goodwill		$ 42,530,000
Gibraltar Private Bank & Trust Company | Common Stock
Business Acquisition [Line Items]
Common stock issued (in dollars per share) | $ / shares		$ 77.00
Number of shares issued per share acquired | $ / shares		$ 1.9749
Common stock issued (shares) | shares		2,787,773
Solomon Parks Title & Escrow
Business Acquisition [Line Items]
Cash consideration					3,300,000
Increase in goodwill due to adjustments					3,400,000
Sabadell United
Business Acquisition [Line Items]
Loans acquired			$ 4,025,946,000
Interest-bearing deposits acquired			$ 4,382,780,000
Number of offices acquired | bank			25
Cash consideration			$ 809,159,000
Percentage of voting interests acquired			100.00%
Increase in goodwill due to adjustments				1,400,000
Goodwill	$ 463,400,000		$ 463,403,000	$ 463,400,000	$ 463,400,000
Sabadell United | Fair Value Adjustments
Business Acquisition [Line Items]
amortization of premiums and accretion of discounts on acquired loans, securities, and deposits						5,100,000
Elimination of amortization of premiums and accretion of discounts on previously acquired loans, securities, FDIC indemnification asset, and deposits						318,500
Allowance for loan and lease losses acquired						1,600,000
Amortization of intangible assets acquired						$ 1,500,000
Sabadell United | Common Stock
Business Acquisition [Line Items]
Common stock issued (shares) | shares			2,610,304

XML

Acquisition Activity - Consideration (Details) - USD ($) $ in Thousands				3 Months Ended
	Mar. 31, 2018	Mar. 23, 2018	Jul. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Total equity consideration				$ 214,659	$ 0
Goodwill	$ 1,236,169			1,236,169		$ 1,188,902	$ 726,856
Gibraltar Private Bank & Trust Company
Business Acquisition [Line Items]
Total equity consideration		$ 214,659
Cash	214,700	7
Total consideration paid		214,666
Fair value of net assets assumed including identifiable intangible assets		172,136
Goodwill		$ 42,530
Gibraltar Private Bank & Trust Company | Common Stock
Business Acquisition [Line Items]
Common stock issued (shares)		2,787,773
Common stock issued		$ 214,659
Sabadell United
Business Acquisition [Line Items]
Total equity consideration			$ 211,043
Cash			809,159
Total consideration paid			1,020,202
Fair value of net assets assumed including identifiable intangible assets			556,799
Goodwill	$ 463,400		$ 463,403	$ 463,400
Sabadell United | Common Stock
Business Acquisition [Line Items]
Common stock issued (shares)			2,610,304
Common stock issued			$ 211,043

XML

Acquisition Activity - Assets Acquired and Liabilities Assumed (Details) - USD ($)	Mar. 31, 2018	Mar. 23, 2018	Jan. 12, 2018	Jul. 31, 2017
Assets
Non-compete agreement			$ 155,900
Gibraltar Private Bank & Trust Company
Assets
Cash and cash equivalents		$ 102,570,000
Investment securities		19,169,000
Equity securities		27,519,000
Loans	$ 1,500,000,000	1,465,319,000
Core deposit intangible assets		18,529,000
Deferred tax asset, net		689,000
Other assets		14,382,000
Total assets acquired		1,648,177,000
Liabilities
Deposit liabilities		1,064,803,000
Long-term borrowings		405,107,000
Other liabilities		6,131,000
Total liabilities assumed		$ 1,476,041,000
Solomon Parks Title & Escrow
Assets
Premise and equipment, net			42,000
Non-compete agreement			156,000
Title Plant investment			15,000
Total assets acquired			213,000
Liabilities
Contingent consideration			343,000
Total liabilities assumed			$ 343,000
Sabadell United
Assets
Cash and cash equivalents				$ 318,834,000
Investment securities				964,123,000
Loans				4,025,946,000
Core deposit intangible assets				66,600,000
Deferred tax asset, net				33,469,000
Other assets				89,745,000
Total assets acquired				5,498,717,000
Liabilities
Deposit liabilities				4,382,780,000
Short-term borrowings				520,539,000
Other liabilities				38,599,000
Total liabilities assumed				$ 4,941,918,000

XML

Acquisition Activity - Pro Forma Information (Details) - Sabadell United $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
Business Acquisition [Line Items]
Net interest income	$ 231,087
Non-interest income	54,755
Net income	$ 43,562

XML

Investment Securities - Schedule of Amortized Cost and Fair Values of Investment Securities, with Gross Unrealized Gains and Losses (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities
Amortized cost	$ 4,668,025	$ 4,647,931
Gross unrealized gain	1,624	5,972
Gross unrealized losses	(127,163)	(63,841)
Estimated fair value	4,542,486	4,590,062
Schedule of Held-to-maturity Securities
Amortized cost	224,241	227,318
Gross unrealized gains	761	1,571
Gross unrealized losses	(5,134)	(925)
Estimated fair value	219,868	227,964
Fair value of securities held as collateral	2,100,000	0
US Treasury Securities
Schedule of Available-for-sale Securities
Amortized cost	6,824
Gross unrealized gain	0
Gross unrealized losses	0
Estimated fair value	6,824
U.S. Government-Sponsored Enterprise Obligations
Schedule of Available-for-sale Securities
Amortized cost	41,001	41,003
Gross unrealized gain	11	18
Gross unrealized losses	(654)	(406)
Estimated fair value	40,358	40,615
Obligations of State and Political Subdivisions
Schedule of Available-for-sale Securities
Amortized cost	267,962	271,451
Gross unrealized gain	1,228	4,246
Gross unrealized losses	(4,156)	(1,493)
Estimated fair value	265,034	274,204
Schedule of Held-to-maturity Securities
Amortized cost	204,404	206,736
Gross unrealized gains	726	1,530
Gross unrealized losses	(4,120)	(275)
Estimated fair value	201,010	207,991
Mortgage-Backed Securities
Schedule of Available-for-sale Securities
Amortized cost	4,277,033	4,221,472
Gross unrealized gain	279	1,461
Gross unrealized losses	(121,215)	(61,028)
Estimated fair value	4,156,097	4,161,905
Schedule of Held-to-maturity Securities
Amortized cost	19,837	20,582
Gross unrealized gains	35	41
Gross unrealized losses	(1,014)	(650)
Estimated fair value	18,858	19,973
Other Securities
Schedule of Available-for-sale Securities
Amortized cost	75,205	114,005
Gross unrealized gain	106	247
Gross unrealized losses	(1,138)	(914)
Estimated fair value	$ 74,173	$ 113,338

XML

Investment Securities - Schedule of Securities with Gross Unrealized Losses Aggregated by Investment Category (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Gross Unrealized Losses
Less than twelve months	$ (70,865)	$ (27,757)
Over twelve months	(56,298)	(36,084)
Total	(127,163)	(63,841)
Estimated Fair Value
Less than twelve months	3,033,959	2,813,985
Over twelve months	1,267,402	1,304,515
Total	4,301,361	4,118,500
Gross Unrealized Losses
Less than twelve months	(4,077)	(265)
Over twelve months	(1,057)	(660)
Total	(5,134)	(925)
Estimated Fair Value
Less than twelve months	150,511	66,150
Over twelve months	21,163	22,300
Total	171,674	88,450
US Treasury Securities
Gross Unrealized Losses
Less than twelve months	0
Over twelve months	0
Total	0
Estimated Fair Value
Less than twelve months	693
Over twelve months	0
Total	693
U.S. Government-Sponsored Enterprise Obligations
Gross Unrealized Losses
Less than twelve months	(419)	(254)
Over twelve months	(235)	(152)
Total	(654)	(406)
Estimated Fair Value
Less than twelve months	29,580	29,744
Over twelve months	9,765	9,848
Total	39,345	39,592
Obligations of State and Political Subdivisions
Gross Unrealized Losses
Less than twelve months	(1,147)	(326)
Over twelve months	(3,009)	(1,167)
Total	(4,156)	(1,493)
Estimated Fair Value
Less than twelve months	96,138	31,601
Over twelve months	66,404	68,609
Total	162,542	100,210
Mortgage-Backed Securities
Gross Unrealized Losses
Less than twelve months	(68,161)	(26,263)
Over twelve months	(53,054)	(34,765)
Total	(121,215)	(61,028)
Estimated Fair Value
Less than twelve months	2,847,244	2,677,338
Over twelve months	1,191,233	1,226,058
Total	4,038,477	3,903,396
Other Securities
Gross Unrealized Losses
Less than twelve months	(1,138)	(914)
Over twelve months	0	0
Total	(1,138)	(914)
Estimated Fair Value
Less than twelve months	60,304	75,302
Over twelve months	0	0
Total	60,304	75,302
Obligations of State and Political Subdivisions
Gross Unrealized Losses
Less than twelve months	(4,066)	(263)
Over twelve months	(54)	(12)
Total	(4,120)	(275)
Estimated Fair Value
Less than twelve months	150,188	65,817
Over twelve months	2,976	3,031
Total	153,164	68,848
Mortgage-Backed Securities
Gross Unrealized Losses
Less than twelve months	(11)	(2)
Over twelve months	(1,003)	(648)
Total	(1,014)	(650)
Estimated Fair Value
Less than twelve months	323	333
Over twelve months	18,187	19,269
Total	$ 18,510	$ 19,602

XML

Investment Securities - Additional Information on Securities in a Continuous Loss Position (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($) Security	Dec. 31, 2017 USD ($) Security
Schedule of Available-for-sale Securities
Number of debt securities with unrealized losses | Security	635	544
Debt securities with unrealized losses (percentage of amortized cost)	2.87%	1.52%
Number of securities | Security	213	210
Amortized cost basis	$ 1,345,920	$ 1,363,559
Unrealized loss	$ 57,355	$ 36,744
Mortgage-backed securities
Schedule of Available-for-sale Securities
Number of securities | Security	184	181
Amortized cost basis	$ 1,263,477	$ 1,280,739
Unrealized loss	$ 54,057	$ 35,412
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities
Number of securities | Security	28	28
Amortized cost basis	$ 72,443	$ 72,820
Unrealized loss	$ 3,063	$ 1,180
Other
Schedule of Available-for-sale Securities
Number of securities | Security	1	1
Amortized cost basis	$ 10,000	$ 10,000
Unrealized loss	$ 235	$ 152

XML

Investment Securities - Schedule of Amortized Cost and Estimated Fair Value of Investment Securities by Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Weighted Average Yield
Within one year or less	2.06%
One through five years	2.04%
After five through ten years	2.36%
Over ten years	2.38%
Weighted average yield	2.38%
Amortized Cost
Within one year or less	$ 6,667
One through five years	134,449
After five through ten years	887,796
Over ten years	3,639,113
Amortized cost	4,668,025
Estimated Fair Value
Within one year or less	6,670
One through five years	132,594
After five through ten years	868,090
Over ten years	3,535,132
Estimated fair value	$ 4,542,486	$ 4,590,062
Weighted Average Yield
Within one year or less	3.04%
One through five years	2.98%
After five through ten years	2.66%
Over ten years	2.56%
Weighted average yield	2.60%
Amortized Cost
Within one year or less	$ 1,445
One through five years	8,369
After five through ten years	45,690
Over ten years	168,737
Amortized cost	224,241	227,318
Estimated Fair Value
Within one year or less	1,448
One through five years	8,370
After five through ten years	45,450
Over ten years	164,600
Estimated fair value	$ 219,868	$ 227,964

XML

Investment Securities - Schedule of Realized Gains and Losses from Sale of Securities Classified as Available for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Realized gains	$ 9	$ 0
Realized losses	(68)	0
Net realized gains (losses)	$ (59)	$ 0

XML

Investment Securities - Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank (FHLB) stock	$ 90,561	$ 95,171
Federal Reserve Bank Stock	79,191	79,191
Equity Securities, FV-NI	9,801	0
Other Investments	9,705	3,008
Marketable Securities, Equity Securities	$ 189,258	$ 177,370

XML

Allowance for Credit Losses and Credit Quality - Schedule of Allowance for Loan Losses for Covered and Non-Covered Loan Portfolios (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 140,891	$ 144,719
Provision for loan and lease losses	7,986	6,154
Transfer of balance to OREO and other	(47)	73
Loans charged-off	(9,116)	(7,291)
Recoveries	4,813	1,235
Allowance for loan losses at end of period	144,527	144,890
Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	13,208	11,241
Provision for (Reversal of) unfunded lending commitments	224	419
Reserve for unfunded commitments at end of period	13,432	11,660
Allowance for credit losses at end of period	$ 157,959	$ 156,550

XML

Allowance for Credit Losses and Credit Quality - Schedule of Allowance for Loan Losses for Legacy and Acquired Loans, by Loan Portfolio (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	$ 140,891	$ 144,719
Provision for (Reversal of) loan losses	7,986	6,154
Transfer of balance to OREO and other	(47)	73
Loans charged-off	(9,116)	(7,291)
Recoveries	4,813	1,235
Allowance for loan losses at end of period	144,527	144,890
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	13,208	11,241
Provision for (Reversal of) unfunded commitments	224	419
Reserve for unfunded commitments at end of period	13,432	11,660
Allowance on loans individually evaluated for impairment	19,698	28,809
Allowance on loans collectively evaluated for impairment	90,696	80,926
Allowance on loans acquired with deteriorated credit quality	157,959	156,550
Loans, net of unearned income:
Loans, net of unearned income	21,706,090	15,132,202
Balance at end of period individually evaluated for impairment	196,532	269,112
Balance at end of period collectively evaluated for impairment	21,027,680	14,365,751
Commercial Loans | Real Estate
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	54,201	49,231
Provision for (Reversal of) loan losses	6,377	1,786
Transfer of balance to OREO and other	(47)	377
Loans charged-off	(114)	(95)
Recoveries	191	196
Allowance for loan losses at end of period	60,608	51,495
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	4,531	3,207
Provision for (Reversal of) unfunded commitments	1,476	1,379
Reserve for unfunded commitments at end of period	6,007	4,586
Allowance on loans individually evaluated for impairment	2,506	1,916
Allowance on loans collectively evaluated for impairment	35,871	26,872
Loans, net of unearned income:
Loans, net of unearned income	9,248,951	7,021,341
Balance at end of period individually evaluated for impairment	78,489	74,351
Balance at end of period collectively evaluated for impairment	8,946,138	6,687,651
Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	53,916	60,939
Provision for (Reversal of) loan losses	294	2,557
Transfer of balance to OREO and other	0	(350)
Loans charged-off	(5,378)	(3,762)
Recoveries	3,698	84
Allowance for loan losses at end of period	52,530	59,468
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	5,309	4,537
Provision for (Reversal of) unfunded commitments	(1,004)	(885)
Reserve for unfunded commitments at end of period	4,305	3,652
Allowance on loans individually evaluated for impairment	14,040	25,056
Allowance on loans collectively evaluated for impairment	36,208	32,383
Loans, net of unearned income:
Loans, net of unearned income	5,325,682	3,975,734
Balance at end of period individually evaluated for impairment	78,725	164,405
Balance at end of period collectively evaluated for impairment	5,211,736	3,778,775
Residential Mortgage
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	9,117	11,249
Provision for (Reversal of) loan losses	(686)	(1,060)
Transfer of balance to OREO and other	0	2
Loans charged-off	(105)	(22)
Recoveries	22	43
Allowance for loan losses at end of period	8,348	10,212
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	555	657
Provision for (Reversal of) unfunded commitments	(15)	(49)
Reserve for unfunded commitments at end of period	540	608
Allowance on loans individually evaluated for impairment	178	113
Allowance on loans collectively evaluated for impairment	2,073	3,907
Loans, net of unearned income:
Loans, net of unearned income	3,971,067	1,296,358
Balance at end of period individually evaluated for impairment	6,041	5,048
Balance at end of period collectively evaluated for impairment	3,826,721	1,176,017
Consumer and Other Loans
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	23,657	23,300
Provision for (Reversal of) loan losses	2,001	2,871
Transfer of balance to OREO and other	0	44
Loans charged-off	(3,519)	(3,412)
Recoveries	902	912
Allowance for loan losses at end of period	23,041	23,715
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	2,813	2,840
Provision for (Reversal of) unfunded commitments	(233)	(26)
Reserve for unfunded commitments at end of period	2,580	2,814
Allowance on loans individually evaluated for impairment	2,974	1,724
Allowance on loans collectively evaluated for impairment	16,544	17,764
Loans, net of unearned income:
Loans, net of unearned income	3,160,390	2,838,769
Balance at end of period individually evaluated for impairment	33,277	25,308
Balance at end of period collectively evaluated for impairment	3,043,085	2,723,308
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	34,133	35,155
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	481,878	497,339
Receivables Acquired with Deteriorated Credit Quality | Commercial Loans | Real Estate
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	22,231	22,707
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	224,324	259,339
Receivables Acquired with Deteriorated Credit Quality | Commercial Loans | Commercial and industrial
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	2,282	2,029
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	35,221	32,554
Receivables Acquired with Deteriorated Credit Quality | Residential Mortgage
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	6,097	6,192
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	138,305	115,293
Receivables Acquired with Deteriorated Credit Quality | Consumer and Other Loans
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	3,523	4,227
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	$ 84,028	$ 90,153

XML

Allowance for Credit Losses and Credit Quality - Investment in Legacy and Acquired Loans by Credit Quality Indicator (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses
Total Loans	$ 21,706,090	$ 20,078,181
Commercial Loans
Financing Receivable, Allowance for Credit Losses
Total Loans	14,574,633	14,073,297
Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Total Loans	1,199,625	1,240,396
Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Total Loans	2,612,244	2,529,885
Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Total Loans	5,437,082	5,167,949
Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Total Loans	5,325,682	5,135,067
Residential and Consumer Portfolio
Financing Receivable, Allowance for Credit Losses
Current	6,966,104	5,857,746
30 or more days past due	165,353	147,138
Total Loans	7,131,457	6,004,884
Residential Mortgage | Residential mortgage
Financing Receivable, Allowance for Credit Losses
Current	3,859,751	2,962,043
30 or more days past due	111,316	94,309
Total Loans	3,971,067	3,056,352
Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Allowance for Credit Losses
Current	2,376,171	2,250,205
30 or more days past due	45,015	42,070
Total Loans	2,421,186	2,292,275
Consumer and Other Loans | Consumer - Indirect Automobile
Financing Receivable, Allowance for Credit Losses
Current	48,587	59,836
30 or more days past due	2,084	2,857
Total Loans	50,671	62,693
Consumer and Other Loans | Consumer - Credit card
Financing Receivable, Allowance for Credit Losses
Current	92,497	95,263
30 or more days past due	764	1,105
Total Loans	93,261	96,368
Consumer and Other Loans | Consumer - Other
Financing Receivable, Allowance for Credit Losses
Current	589,098	490,399
30 or more days past due	6,174	6,797
Total Loans	595,272	497,196
Pass | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	14,078,168	13,564,833
Pass | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	1,153,604	1,189,490
Pass | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	2,464,072	2,388,715
Pass | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	5,335,816	5,104,074
Pass | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	5,124,676	4,882,554
Special Mention | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	200,701	209,925
Special Mention | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	16,399	20,351
Special Mention | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	83,356	82,114
Special Mention | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	45,905	19,311
Special Mention | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	55,041	88,149
Substandard | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	244,234	258,794
Substandard | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	29,610	30,541
Substandard | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	56,409	56,590
Substandard | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	51,089	42,702
Substandard | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	107,126	128,961
Doubtful | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	51,530	39,627
Doubtful | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	12	14
Doubtful | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	8,407	2,466
Doubtful | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	4,272	1,744
Doubtful | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	$ 38,839	35,403
Loss | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable		118
Loss | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable		0
Loss | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable		0
Loss | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable		118
Loss | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable		$ 0

XML

Allowance for Credit Losses and Credit Quality - Schedule of Investment in Legacy Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Impaired
Unpaid Principal Balance	$ 219,771		$ 283,629
Recorded Investment	196,532		238,127
Related allowance	(2,974)		(2,856)
Average Recorded Investment	189,754	$ 274,131
Interest Income Recognized	1,695	1,523
Commercial Loans
Financing Receivable, Impaired
Unpaid Principal Balance	178,886		237,922
Recorded Investment	157,214		194,201
Related allowance	(19,698)		(17,352)
Average Recorded Investment	150,255	244,095
Interest Income Recognized	1,280	1,198
Residential Mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	6,440		7,183
Recorded Investment	6,041		6,749
Related allowance	(16,546)		(14,324)
Average Recorded Investment	6,064	5,070
Interest Income Recognized	56	47
Consumer and Other Loans
Financing Receivable, Impaired
Unpaid Principal Balance	34,445		38,524
Recorded Investment	33,277		37,177
Related allowance	(178)		(172)
Average Recorded Investment	33,435	24,966
Interest Income Recognized	359	278
With No Related Allowance Recorded | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Impaired
Unpaid Principal Balance	11,153		13,763
Recorded Investment	11,153		13,013
Average Recorded Investment	10,470	0
Interest Income Recognized	144	0
With No Related Allowance Recorded | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	43,562		50,867
Recorded Investment	36,042		44,482
Average Recorded Investment	36,277	37,197
Interest Income Recognized	334	339
With No Related Allowance Recorded | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	10,575		15,370
Recorded Investment	10,449		14,975
Average Recorded Investment	10,557	5,988
Interest Income Recognized	98	17
With No Related Allowance Recorded | Commercial Loans | Commercial and industrial
Financing Receivable, Impaired
Unpaid Principal Balance	45,720		103,013
Recorded Investment	36,829		70,254
Average Recorded Investment	27,832	90,664
Interest Income Recognized	385	448
With No Related Allowance Recorded | Commercial Loans | Residential mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	1,083		2,004
Recorded Investment	1,083		2,001
Average Recorded Investment	1,090	735
Interest Income Recognized	12	5
With No Related Allowance Recorded | Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Impaired
Unpaid Principal Balance	31		5,906
Recorded Investment	31		5,634
Average Recorded Investment	32	4,158
Interest Income Recognized	0	40
With No Related Allowance Recorded | Consumer and Other Loans | Consumer - Other
Financing Receivable, Impaired
Unpaid Principal Balance	0		75
Recorded Investment	0		75
With An Allowance Recorded | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Impaired
Unpaid Principal Balance	236		238
Recorded Investment	154		156
Related allowance	(18)		(19)
Average Recorded Investment	153	1,984
Interest Income Recognized	1	1
With An Allowance Recorded | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	17,536		13,314
Recorded Investment	17,419		13,287
Related allowance	(1,860)		(949)
Average Recorded Investment	17,608	20,980
Interest Income Recognized	112	79
With An Allowance Recorded | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	3,399		6,051
Recorded Investment	3,272		5,872
Related allowance	(628)		(620)
Average Recorded Investment	3,302	8,587
Interest Income Recognized	10	94
With An Allowance Recorded | Commercial Loans | Commercial and industrial
Financing Receivable, Impaired
Unpaid Principal Balance	46,705		35,306
Recorded Investment	41,896		32,162
Related allowance	(14,040)		(12,736)
Average Recorded Investment	44,056	78,695
Interest Income Recognized	196	220
With An Allowance Recorded | Residential Mortgage | Residential mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	5,357		5,179
Recorded Investment	4,958		4,748
Related allowance	(178)		(172)
Average Recorded Investment	4,974	4,335
Interest Income Recognized	44	42
With An Allowance Recorded | Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Impaired
Unpaid Principal Balance	28,917		27,189
Recorded Investment	28,187		26,575
Related allowance	(2,435)		(2,358)
Average Recorded Investment	28,203	16,713
Interest Income Recognized	292	179
With An Allowance Recorded | Consumer and Other Loans | Consumer - Indirect Automobile
Financing Receivable, Impaired
Unpaid Principal Balance	1,004		1,034
Recorded Investment	656		679
Related allowance	(75)		(79)
Average Recorded Investment	717	767
Interest Income Recognized	5	7
With An Allowance Recorded | Consumer and Other Loans | Consumer - Other
Financing Receivable, Impaired
Unpaid Principal Balance	4,493		4,320
Recorded Investment	4,403		4,214
Related allowance	(464)		$ (419)
Average Recorded Investment	4,483	3,328
Interest Income Recognized	$ 62	$ 52

XML

Goodwill and Other Intangible Assets - Schedule of Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands		3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2017
Goodwill
Balance at beginning of the period		$ 1,188,902		$ 726,856
Goodwill acquired during the year (preliminary allocation)				462,046
Goodwill acquired during the year (preliminary allocation) and adjustments		47,267
Balance at end of the period	$ 1,236,169	1,236,169	$ 1,236,169
Operating Segments | IBERIABANK
Goodwill
Balance at beginning of the period		1,160,559		698,513
Goodwill acquired during the year (preliminary allocation)				462,046
Goodwill acquired during the year (preliminary allocation) and adjustments		43,887
Balance at end of the period	1,204,446	1,204,446	1,204,446
Operating Segments | IMC
Goodwill
Balance at beginning of the period		23,178		23,178
Goodwill acquired during the year (preliminary allocation)				0
Goodwill acquired during the year (preliminary allocation) and adjustments		0
Balance at end of the period	23,178	23,178	23,178
Operating Segments | LTC
Goodwill
Balance at beginning of the period		5,165		5,165
Goodwill acquired during the year (preliminary allocation)				$ 0
Goodwill acquired during the year (preliminary allocation) and adjustments		3,380
Balance at end of the period	8,545	$ 8,545	8,545
Gibraltar Private Bank & Trust Company
Goodwill
Goodwill acquired during the year (preliminary allocation) and adjustments	$ 42,500
Solomon Parks Title & Escrow
Goodwill
Goodwill acquired during the year (preliminary allocation) and adjustments			$ 3,400

XML

Goodwill and Other Intangible Assets - Narrative (Detail) - USD ($)		3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 23, 2018	Jan. 12, 2018	Dec. 31, 2017	Jul. 31, 2017
Goodwill
Goodwill acquired during the year (preliminary allocation) and adjustments		$ 47,267,000
Non-compete agreement				$ 155,900
Title plant assets	$ 6,800,000	6,800,000			$ 6,700,000
Gibraltar Private Bank & Trust Company [Member]
Goodwill
Goodwill acquired during the year (preliminary allocation) and adjustments	$ 42,500,000
Core deposit intangible assets			$ 18,529,000
Sabadell United
Goodwill
Goodwill acquired during the year (preliminary allocation) and adjustments		$ 1,400,000
Core deposit intangible assets						$ 66,600,000

XML

Goodwill and Other Intangible Assets - Schedule of Mortgage Servicing Rights at Carrying Value (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 129,163
Accumulated Amortization	(48,034)	(53,006)
Net Carrying Amount	89,740	76,157
Mortgage servicing rights
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,030	9,588
Accumulated Amortization	(4,128)	(3,931)
Net Carrying Amount	$ 5,902	$ 5,657

XML

Goodwill and Other Intangible Assets - Schedule of Definite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 129,163
Accumulated Amortization	(48,034)	(53,006)
Net Carrying Amount	89,740	76,157
Core deposit intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	136,183	127,957
Accumulated Amortization	(46,736)	(51,971)
Net Carrying Amount	89,447	75,986
Customer relationship intangible asset
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,385	1,143
Accumulated Amortization	(1,262)	(996)
Net Carrying Amount	123	147
Non-compete agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	206	63
Accumulated Amortization	(36)	(39)
Net Carrying Amount	$ 170	$ 24

XML

Derivative Instruments and Other Hedging Activities - Schedule of Outstanding Derivative Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value of Derivatives
Derivative Asset	$ 17,072	$ 31,265
Derivative Liability	32,154	25,154
Notional Amount of Derivatives
Derivative assets	1,932,456	1,609,472
Derivative liabilities	1,729,766	1,721,752
Designated as Hedging Instruments
Fair Value of Derivatives
Derivative Asset	0	0
Derivative Liability	0	0
Notional Amount of Derivatives
Derivative assets	108,500	0
Derivative liabilities	0	108,500
Designated as Hedging Instruments | Interest rate contracts
Notional Amount of Derivatives
Derivative assets	108,500	0
Derivative liabilities	0	108,500
Designated as Hedging Instruments | Interest rate contracts | Other Assets
Fair Value of Derivatives
Derivative Asset	0	0
Designated as Hedging Instruments | Interest rate contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	0	0
Not Designated as Hedging Instruments
Notional Amount of Derivatives
Derivative assets	1,823,956	1,609,472
Derivative liabilities	1,729,766	1,613,252
Not Designated as Hedging Instruments | Other Assets
Fair Value of Derivatives
Derivative Asset	17,072	31,265
Not Designated as Hedging Instruments | Other Liabilities
Fair Value of Derivatives
Derivative Liability	32,154	25,154
Not Designated as Hedging Instruments | Interest rate contracts
Notional Amount of Derivatives
Derivative assets	1,356,990	1,218,464
Derivative liabilities	1,276,990	1,218,464
Not Designated as Hedging Instruments | Interest rate contracts | Other Assets
Fair Value of Derivatives
Derivative Asset	5,827	20,446
Not Designated as Hedging Instruments | Interest rate contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	25,771	16,191
Not Designated as Hedging Instruments | Foreign exchange contracts
Notional Amount of Derivatives
Derivative assets	628	268
Derivative liabilities	628	268
Not Designated as Hedging Instruments | Foreign exchange contracts | Other Assets
Fair Value of Derivatives
Derivative Asset	2	7
Not Designated as Hedging Instruments | Foreign exchange contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	2	7
Not Designated as Hedging Instruments | Forward sales contracts
Notional Amount of Derivatives
Derivative assets	96,810	82,347
Derivative liabilities	215,918	142,578
Not Designated as Hedging Instruments | Forward sales contracts | Other Assets
Fair Value of Derivatives
Derivative Asset	2,851	136
Not Designated as Hedging Instruments | Forward sales contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	703	279
Not Designated as Hedging Instruments | Written and purchased options
Notional Amount of Derivatives
Derivative assets	339,852	278,638
Derivative liabilities	164,341	165,198
Not Designated as Hedging Instruments | Written and purchased options | Other Assets
Fair Value of Derivatives
Derivative Asset	8,383	10,654
Not Designated as Hedging Instruments | Written and purchased options | Other Liabilities
Fair Value of Derivatives
Derivative Liability	5,667	8,656
Not Designated as Hedging Instruments | Other contracts
Notional Amount of Derivatives
Derivative assets	29,676	29,755
Derivative liabilities	71,889	86,744
Not Designated as Hedging Instruments | Other contracts | Other Assets
Fair Value of Derivatives
Derivative Asset	9	22
Not Designated as Hedging Instruments | Other contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	$ 11	$ 21

XML

Derivative Instruments and Other Hedging Activities - Narrative (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional amount of derivative liabilities	$ 1,729,766	$ 1,721,752
Cash as collateral for derivative transactions	0	(552)
Cash Posted As Variation Margin for Derivatives	28,800	5,100
Not Designated as Hedging Instruments
Derivative [Line Items]
Notional amount of derivative liabilities	1,729,766	1,613,252
Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Notional amount of derivative liabilities	$ 71,889	$ 86,744

XML

Derivative Instruments and Other Hedging Activities - Reconciliation of Gross Amounts in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative assets
Gross derivative assets	$ 11,483	$ 29,056
Gross amounts not offset in the Balance Sheet, derivatives	(548)	(12,469)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	10,935	16,587
Derivative liabilities
Gross derivative liabilities	31,358	16,191
Gross amounts not offset in the Balance Sheet, derivatives	(548)	(12,469)
Gross amounts not offset in the Balance Sheet, collateral	0	(552)
Net derivative liabilities	30,810	3,170
Written and purchased options
Derivative assets
Gross derivative assets	5,656	8,610
Gross amounts not offset in the Balance Sheet, derivatives	0	0
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	5,656	8,610
Derivative liabilities
Gross derivative liabilities	5,587
Gross amounts not offset in the Balance Sheet, derivatives	0
Gross amounts not offset in the Balance Sheet, collateral	0
Net derivative liabilities	5,587
Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	5,827
Gross amounts not offset in the Balance Sheet, derivatives	(548)
Gross amounts not offset in the Balance Sheet, collateral	0
Net derivative assets	5,279
Derivative liabilities
Gross derivative liabilities	0	0
Gross amounts not offset in the Balance Sheet, derivatives	0	0
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	0	0
Not Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets		20,446
Gross amounts not offset in the Balance Sheet, derivatives		(12,469)
Gross amounts not offset in the Balance Sheet, collateral		0
Net derivative assets		7,977
Derivative liabilities
Gross derivative liabilities	25,771	16,191
Gross amounts not offset in the Balance Sheet, derivatives	(548)	(12,469)
Gross amounts not offset in the Balance Sheet, collateral	0	(552)
Net derivative liabilities	$ 25,223	$ 3,170

XML

Derivative Instruments and Other Hedging Activities - Effect of Hedging Instruments on Consolidated Financial Statements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts | Interest expense
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in OCI, net of taxes	$ 2,549	$ 73
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income, net of taxes	(116)	(45)
Amount of Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0
Not Designated as Hedging Instruments
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in Income on Derivatives	5,086	1,423
Not Designated as Hedging Instruments | Interest rate contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in Income on Derivatives	1,049	1,117
Not Designated as Hedging Instruments | Foreign exchange contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in Income on Derivatives	5	7
Not Designated as Hedging Instruments | Forward sales contracts | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in Income on Derivatives	3,387	(360)
Not Designated as Hedging Instruments | Written and purchased options | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in Income on Derivatives	648	655
Not Designated as Hedging Instruments | Other contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (3)	$ 4

XML

Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	$ 81,173	$ 72,992
Income Tax Expense (Benefit)	$ 17,552	$ 22,519
Effective Income Tax Rate Reconciliation, Percent	21.60%	30.90%
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense (Benefit)	$ 51,000

XML

Income Taxes Income Taxes (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Income Tax Disclosure [Abstract]
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense (Benefit)	$ 51.0

XML

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	May 07, 2018	Mar. 31, 2018	Mar. 23, 2018	May 09, 2016	Aug. 05, 2015	Dec. 31, 2017	Jun. 30, 2016
Class of Stock [Line Items]
Liquidation preference value				$ 137,500
Carrying Amount		$ 132,097				$ 132,097
Number of shares authorized to be repurchased							950,000
Shares authorized to be repurchased		747,494
Series B Preferred Stock
Class of Stock [Line Items]
Ownership per share					6.625%
Liquidation preference value					$ 80,000
Carrying Amount		$ 76,812				76,812
Series C Preferred Stock
Class of Stock [Line Items]
Ownership per share				6.60%
Liquidation preference value				$ 57,500
Carrying Amount		55,285				$ 55,285
Gibraltar Private Bank & Trust Company
Class of Stock [Line Items]
Cash consideration		$ 214,700	$ 7
Gibraltar Private Bank & Trust Company | Common Stock
Class of Stock [Line Items]
Common stock issued (shares)			2,787,773
Common stock issued			$ 214,659
Common stock issued (in dollars per share)			$ 77.00
Number of shares issued per share acquired			$ 1.9749
Subsequent Event
Class of Stock [Line Items]
Treasury stock acquired (shares)	180,000
Treasury stock acquired	$ 13,700

XML

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Actual Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Consolidated
Tier 1 Leverage
Minimum amount	$ 1,076,933	$ 1,073,381
Minimum ratio	4.00%	4.00%
Actual amount	$ 2,685,315	$ 2,509,496
Actual ratio	9.97%	9.35%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,067,284	$ 1,011,732
Minimum ratio	4.50%	4.50%
Actual amount	$ 2,553,218	$ 2,377,398
Actual ratio	10.77%	10.57%
Tier 1 Risk-Based Capital (1)
Minimum amount	$ 1,423,046	$ 1,348,977
Minimum ratio	6.00%	6.00%
Actual amount	$ 2,685,315	$ 2,509,496
Actual ratio	11.32%	11.16%
Total Risk-Based Capital (1)
Minimum amount	$ 1,897,394	$ 1,798,635
Minimum ratio	8.00%	8.00%
Actual amount	$ 2,959,774	$ 2,780,095
Actual ratio	12.48%	12.37%
IBERIABANK
Tier 1 Leverage
Minimum amount	$ 1,074,579	$ 1,070,789
Minimum ratio	4.00%	4.00%
Well capitalized amount	$ 1,343,223	$ 1,338,487
Well capitalized ratio	5.00%	5.00%
Actual amount	$ 2,640,916	$ 2,437,275
Actual ratio	9.83%	9.10%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,065,059	$ 1,009,553
Minimum ratio	4.50%	4.50%
Well capitalized amount	$ 1,538,418	$ 1,458,243
Well capitalized ratio	6.50%	6.50%
Actual amount	$ 2,640,916	$ 2,437,275
Actual ratio	11.16%	10.86%
Tier 1 Risk-Based Capital (1)
Minimum amount	$ 1,420,078	$ 1,346,070
Minimum ratio	6.00%	6.00%
Well capitalized amount	$ 1,893,437	$ 1,794,760
Well capitalized ratio	8.00%	8.00%
Actual amount	$ 2,640,916	$ 2,437,275
Actual ratio	11.16%	10.86%
Total Risk-Based Capital (1)
Minimum amount	$ 1,893,437	$ 1,794,760
Minimum ratio	8.00%	8.00%
Well capitalized amount	$ 2,366,797	$ 2,243,450
Well capitalized ratio	10.00%	10.00%
Actual amount	$ 2,798,875	$ 2,591,374
Actual ratio	11.83%	11.55%

XML

Earnings Per Share - Schedule of Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings per common share - basic:
Net income	$ 63,621	$ 50,473
Less: Preferred stock dividends	3,598	3,599
Less: Dividends and undistributed earnings allocated to unvested restricted shares	639	346
Net income allocated to common shareholders - basic	$ 59,384	$ 46,528
Weighted average common shares outstanding	53,616	46,123
Earnings per common share - basic (in usd per share)	$ 1.11	$ 1.01
Earnings per common share - diluted:
Net income allocated to common shareholders - basic	$ 59,384	$ 46,528
Adjustment for undistributed earnings allocated to unvested restricted shares	(18)	(37)
Earnings Allocated to Common Shareholders	$ 59,366	$ 46,491
Weighted average common shares outstanding	53,616	46,123
Dilutive potential common shares	351	373
Weighted average common shares outstanding - diluted	53,967	46,496
Earnings per common share - diluted (in usd per share)	$ 1.10	$ 1.00

XML

Earnings Per Share - Narrative (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share
Weighted average number of shares held by Recognition and Retention Plan excluded from the calculation for basic shares outstanding	606,442	406,896
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from the computation of earnings per share	156,737	70,456

XML

Share-Based Compensation - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards shares under approved incentive compensation plans	1,166,797
Share-based compensation maximum option term (in years)	10 years
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned share-based compensation associated with awards	$ 2.8
Unrecognized compensation cost related to stock options expected to be recognized over a weighted-average period	3 years 2 months 18 days
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned share-based compensation associated with awards	$ 39.0	$ 21.4
Unrecognized compensation cost related to stock options expected to be recognized over a weighted-average period	1 year 6 months
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Phantom Stock Awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years

XML

Share-Based Compensation - Activity Related to Stock Options (Detail) - Stock Option Awards - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Number of shares
Balance at beginning of the period (in shares)	686,366,000	721,538,000
Granted (in shares)	92,162,000	70,433,000
Exercised (in shares)	(21,212,000)	(24,457,000)
Forfeited or expired (in shares)	(14,513,000)	(12,539,000)
Balance at end of the period (in shares)	742,803,000	754,975,000
Exercisable at period end (in shares)	519,496,000	509,347,000
Weighted Average Exercise Price
Balance at beginning of the period (in usd per share)	$ 58.24	$ 55.38
Granted (in usd per share)	82.20	85.52
Exercised (in usd per share)	52.10	53.85
Forfeited or expired (in usd per share)	65.27	75.77
Balance at end of the period (in usd per share)	61.25	57.90
Exercisable at period end (in usd per share)	$ 56.53	$ 55.78

XML

Share-Based Compensation - Estimate Fair Value of Stock Option Awards with Weighted-Average Assumptions (Detail) - Stock Option Awards - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	1.80%	1.70%
Expected volatility	24.30%	24.90%
Risk-free interest rate	2.70%	2.10%
Expected term (in years)	5 years 8 months 18 days	5 years 7 months
Weighted-average grant-date fair value	$ 18.36	$ 18.75

XML

Share-Based Compensation - Compensation Expense Included in Non-Interest Expense and Related Income Tax Benefits (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 312	$ 444
Income tax benefit	23	68
Restricted Stock And Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	4,422	3,277
Income tax benefit	929	1,147
Phantom Stock and Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 2,996	$ 3,053

XML

Share-Based Compensation - Unvested Restricted Stock Award Activity (Detail) - Restricted Stock And Restricted Stock Units - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of the period (in shares)	738,187,000	543,258,000
Granted (in shares)	199,958,000	146,175,000
Forfeited (in shares)	(43,405,000)	(4,105,000)
Earned and issued (in shares)	(115,877,000)	(157,753,000)
Balance at end of the period (in shares)	778,863,000	527,575,000

XML

Share-Based Compensation - Schedule of Share and Dividend Equivalent Share Award Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Value of share equivalents
Market price of Company's stock	$ 78.00	$ 79.10
Phantom Stock and Performance Stock Units
Number of share equivalents
Balance at beginning of the period (in shares)	393,844,000	472,830,000
Granted (in shares)	129,234,000	96,897,000
Forfeited share equivalents (in shares)	(24,460,000)	(5,330,000)
Vested share equivalents (in shares)	(121,758,000)	(143,643,000)
Balance at end of the period (in shares)	376,860,000	420,754,000
Value of share equivalents
Balance at beginning of the period (in shares)	$ 30,523	$ 39,600
Granted (in shares)	10,080	7,665
Forfeited share equivalents (in shares)	(1,908)	(422)
Vested share equivalents (in shares)	(10,187)	(12,024)
Balance at end of the period (in shares)	$ 29,395	$ 33,282

XML

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Assets
Securities available for sale, at fair value	$ 4,542,486,000	$ 4,590,062,000
Equity Securities, FV-NI	9,801,000	0
Mortgage loans held for sale	110,348,000	134,916,000
Derivative instruments	11,483,000	29,056,000
Liabilities
Derivative instruments	31,358,000	16,191,000
Fair value assets transferred from Level 1 to Level 2	0
Level 1
Assets
Securities available for sale, at fair value	0	0
Equity Securities, FV-NI	0
Level 2
Assets
Securities available for sale, at fair value	4,542,486,000	4,590,062,000
Equity Securities, FV-NI	9,801,000
Level 3
Assets
Securities available for sale, at fair value	0	0
Equity Securities, FV-NI	0
Recurring
Assets
Securities available for sale, at fair value	4,542,486,000	4,590,062,000
Equity Securities, FV-NI	9,801,000
Mortgage loans held for sale	110,348,000	134,916,000
Derivative instruments	17,072,000	31,265,000
Total, Assets	4,679,707,000	4,756,243,000
Liabilities
Derivative instruments	32,154,000	25,154,000
Total	32,154,000	25,154,000
Recurring | Level 1
Assets
Securities available for sale, at fair value	0	0
Equity Securities, FV-NI	0
Mortgage loans held for sale	0	0
Derivative instruments	0	0
Total, Assets	0	0
Liabilities
Derivative instruments	0	0
Total	0	0
Recurring | Level 2
Assets
Securities available for sale, at fair value	4,542,486,000	4,590,062,000
Equity Securities, FV-NI	9,801,000
Mortgage loans held for sale	110,348,000	134,916,000
Derivative instruments	17,072,000	31,265,000
Total, Assets	4,679,707,000	4,756,243,000
Liabilities
Derivative instruments	32,154,000	25,154,000
Total	32,154,000	25,154,000
Recurring | Level 3
Assets
Securities available for sale, at fair value	0	0
Equity Securities, FV-NI	0
Mortgage loans held for sale	0	0
Derivative instruments	0	0
Total, Assets	0	0
Liabilities
Derivative instruments	0	0
Total	$ 0	$ 0

XML

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Unpaid Principal Balance	$ 219,771	$ 283,629
Related allowance	2,974	2,856
Nonrecurring
Assets
Loans	85,269	71,210
OREO, net	2,234	3,029
Total	87,503	74,239
Nonrecurring | Level 1
Assets
Loans	0	0
OREO, net	0	0
Total	0	0
Nonrecurring | Level 2
Assets
Loans	0	0
OREO, net	0	0
Total	0	0
Nonrecurring | Level 3
Assets
Loans	85,269	71,210
OREO, net	2,234	3,029
Total	$ 87,503	$ 74,239

XML

Fair Value Measurements - Summary of Difference Between the Aggregate Fair Value and the Aggregate Unpaid Principal Balance for Mortgage Loans Held for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value of acquired loans at acquisition	$ 17,000		$ 15,000
Net gains (losses) resulting from change in fair value of loans held-for-investment	(749)	$ (409)
Mortgages Held For Sale at Fair Value
Aggregate fair value	110,348		134,916
Aggregate unpaid principal	107,849		131,276
Aggregate fair value less unpaid principal	2,499		$ 3,640
Net gains (losses) resulting from change in fair value of loans held-for-sale	$ (1,100)	$ 839

XML

Fair Value of Financial Instruments - Estimated Fair Values and Carrying Amounts of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Financial Assets
Securities available for sale, at fair value	$ 4,542,486	$ 4,590,062
Equity Securities, FV-NI	9,801	0
Financial Assets	110,348	134,916
Derivative Asset	17,072	31,265
Cash and cash equivalents	564,092	625,724	$ 1,301,118	$ 1,362,126
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	224,241	227,318
Financial Liabilities
Financial Liabilities	22,971,192	21,466,717	$ 17,312,265
Short-term Debt	900,496	991,297
Long-term debt	1,449,302	1,495,835
Derivative instruments	32,154	25,154
Level 1
Financial Assets
Securities available for sale, at fair value	0	0
Equity Securities, FV-NI	0
Financial Assets	0	0
Derivative Asset	0	0
Cash and cash equivalents	564,092	625,724
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	0	0
Loans and Leases Receivable, Net Amount	0	0
Financial Liabilities
Financial Liabilities	0	0
Short-term Debt	525,496	516,297
Long-term debt	0	0
Derivative instruments	0	0
Level 2
Financial Assets
Securities available for sale, at fair value	4,542,486	4,590,062
Equity Securities, FV-NI	9,801
Financial Assets	110,348	134,916
Derivative Asset	17,072	31,265
Cash and cash equivalents	0	0
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	219,868	227,964
Loans and Leases Receivable, Net Amount	0	0
Financial Liabilities
Financial Liabilities	22,970,554	21,460,782
Short-term Debt	375,000	475,000
Long-term debt	0	0
Derivative instruments	32,154	25,154
Level 3
Financial Assets
Securities available for sale, at fair value	0	0
Equity Securities, FV-NI	0
Financial Assets	0	0
Derivative Asset	0	0
Cash and cash equivalents	0	0
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	0	0
Loans and Leases Receivable, Net Amount	21,495,639	19,826,857
Financial Liabilities
Financial Liabilities	0	0
Short-term Debt	0	0
Long-term debt	1,429,335	1,476,899
Derivative instruments	0	0
Carrying Amount
Financial Assets
Securities available for sale, at fair value	4,542,486	4,590,062
Equity Securities, FV-NI	9,801
Financial Assets	110,348	134,916
Derivative Asset	17,072	31,265
Cash and cash equivalents	564,092	625,724
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	224,241	227,318
Loans and Leases Receivable, Net Amount	21,561,563	19,937,290
Financial Liabilities
Financial Liabilities	22,971,192	21,466,717
Short-term Debt	900,496	991,297
Long-term debt	1,449,302	1,495,835
Derivative instruments	32,154	25,154
Fair Value
Financial Assets
Securities available for sale, at fair value	4,542,486	4,590,062
Equity Securities, FV-NI	9,801
Financial Assets	110,348	134,916
Derivative Asset	17,072	31,265
Cash and cash equivalents	564,092	625,724
Securities held to maturity (fair values of $219,868 and $227,964, respectively)	219,868	227,964
Loans and Leases Receivable, Net Amount	21,495,639	19,826,857
Financial Liabilities
Financial Liabilities	22,970,554	21,460,782
Short-term Debt	900,496	991,297
Long-term debt	1,429,335	1,476,899
Derivative instruments	$ 32,154	$ 25,154

XML

Business Segments (Detail)	3 Months Ended
	Mar. 31, 2018 Segment
Segment Reporting [Abstract]
Number of business segments	3

XML

Business Segments - Schedule of Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information
Interest and dividend income	$ 270,543	$ 192,533
Interest expense	37,654	19,715
Net interest income	232,889	172,818
Provision for loan and lease losses	7,986	6,154
Mortgage income	9,595	14,115
Service charges on deposit accounts	12,908	11,153
Title revenue	5,027	4,741
Other non-interest income	29,944	26,268
Allocated expenses	0	0
Non-interest expense	188,296	138,796
Income before income tax expense	81,173	72,992
Income tax expense	17,552	22,519
Net income	63,621	50,473
Total loans, leases, and loans held for sale, net of unearned income	21,816,438	15,254,535
Total assets	29,472,637	22,008,479	$ 27,904,129
Total deposits	22,971,192	17,312,265	$ 21,466,717
Average assets	28,132,219	21,861,501
Operating Segments | IBERIABANK
Segment Reporting Information
Interest and dividend income	268,775	190,823
Interest expense	37,654	19,715
Net interest income	231,121	171,108
Provision for loan and lease losses	7,991	6,158
Mortgage income	0	0
Title revenue	0	0
Other non-interest income	29,906	26,284
Allocated expenses	(1,479)	(2,174)
Non-interest expense	171,816	119,429
Income before income tax expense	82,699	73,979
Income tax expense	18,540	22,829
Net income	64,159	51,150
Total loans, leases, and loans held for sale, net of unearned income	21,652,223	15,072,661
Total assets	29,243,983	21,774,586
Total deposits	22,959,061	17,306,328
Average assets	27,924,587	21,550,930
Operating Segments | IMC
Segment Reporting Information
Interest and dividend income	1,767	1,709
Interest expense	0	0
Net interest income	1,767	1,709
Provision for loan and lease losses	(5)	(4)
Mortgage income	9,595	14,115
Title revenue	0	0
Other non-interest income	38	(10)
Allocated expenses	1,166	1,656
Non-interest expense	11,916	15,167
Income before income tax expense	(1,677)	(1,005)
Income tax expense	(410)	(322)
Net income	(1,267)	(683)
Total loans, leases, and loans held for sale, net of unearned income	164,215	181,874
Total assets	205,497	209,911
Total deposits	12,131	5,937
Average assets	185,742	286,694
Operating Segments | LTC
Segment Reporting Information
Interest and dividend income	1	1
Interest expense	0	0
Net interest income	1	1
Provision for loan and lease losses	0	0
Mortgage income	0	0
Title revenue	5,027	4,741
Other non-interest income	0	(6)
Allocated expenses	313	518
Non-interest expense	4,564	4,200
Income before income tax expense	151	18
Income tax expense	(578)	12
Net income	729	6
Total loans, leases, and loans held for sale, net of unearned income	0	0
Total assets	23,157	23,982
Total deposits	0	0
Average assets	$ 21,890	$ 23,877

XML

Commitments and Contingencies - Narrative (Detail) - USD ($) $ in Millions		3 Months Ended
	Dec. 11, 2017	Mar. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Fair value of guarantees under commercial and standby letters of credit		$ 2.1	$ 2.1
Settled Litigation [Member]
Loss Contingencies [Line Items]
Settlement amount	$ 11.7
Pending Litigation [Member]
Loss Contingencies [Line Items]
Damages sought		$ 11.7

XML

Commitments and Contingencies - Summary of Financial Instruments Outstanding (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments to grant loans	$ 319,318	$ 342,305
Unfunded commitments under lines of credit	6,340,135	6,060,034
Commercial and standby letters of credit	211,070	210,002
Reserve for unfunded lending commitments	$ 13,432	$ 13,208	$ 11,660	$ 11,241

XML

Label	Element	Value
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (345,000)	[1]

[1] Cumulative-effect adjustment to beginning retained earnings for fair value adjustments related to the reclassification of certain equity investments in accordance with ASU 2016-01, adopted as of January 1, 2018.