Loans and Allowances for Credit Losses

Loans

Loans are either secured or unsecured based on the type of loan and the financial condition of the borrower. Repayment is generally expected from cash flow or proceeds from the sale of selected assets of the borrower. BOK Financial is exposed to risk of loss on loans due to the borrower’s difficulties, which may arise from any number of factors, including problems within the respective industry or local economic conditions. Access to collateral, in the event of borrower default, is reasonably assured through adherence to applicable lending laws and through sound lending standards and credit review procedures. Accounting policies for all loans, excluding residential mortgage loans guaranteed by U.S. government agencies, are as follows.

Interest is accrued at the applicable interest rate on the principal amount outstanding. Loans are placed on nonaccruing status when, in the opinion of management, full collection of principal or interest is uncertain. Internally risk graded loans are individually evaluated for nonaccruing status quarterly. Non-risk graded loans are generally placed on nonaccruing status when more than 90 days past due or within 60 days of being notified of the borrower's bankruptcy filing. Interest previously accrued but not collected is charged against interest income when the loan is placed on nonaccruing status. Payments on nonaccruing loans are applied to principal or recognized as interest income, according to management’s judgment as to the collectability of principal. Loans may be returned to accruing status when, in the opinion of management, full collection of principal and interest, including principal previously charged off, is probable based on improvements in the borrower’s financial condition or a sustained period of performance.

Loans to borrowers experiencing financial difficulties may be modified in troubled debt restructurings ("TDRs"). All TDRs are classified as nonaccruing, excluding loans guaranteed by U.S. government agencies. Modifications generally consist of extension of payment terms or interest rate concessions and may result either voluntarily through negotiations with the borrower or involuntarily through court order. Generally, principal and accrued but unpaid interest is not voluntarily forgiven.

Performing loans may be renewed under the current collateral value, debt service ratio and other underwriting standards. Nonaccruing loans may be renewed and will remain classified as nonaccruing.

All loans are charged off when the loan balance or a portion of the loan balance is no longer supported by the paying capacity of the borrower or when the required cash flow is reduced in a TDR. The charge-off amount is determined through a quarterly evaluation of available cash resources and collateral value and charge-offs are taken in the quarter in which the loss is identified. Non-risk graded loans that are past due between 60 days and 180 days, based on the loan product type, are charged off. Loans to borrowers whose personal obligation has been discharged through Chapter 7 bankruptcy proceedings are charged off within 60 days of notice of the bankruptcy filing, regardless of payment status.

Loan origination and commitment fees and direct loan acquisition and origination costs are deferred and amortized as an adjustment to yield over the life of the loan or over the commitment period, as applicable.

Qualifying residential mortgage loans guaranteed by U.S. government agencies have been sold into GNMA pools. Under certain performance conditions specified in government programs, the Company may have the right, but not the obligation to repurchase loans from GNMA pools. These loans no longer qualify for sale accounting and are recognized in the Consolidated Balance Sheets. Guaranteed loans are considered impaired because we do not expect to receive all principal and interest based on the loan's contractual terms. The principal balance continues to be guaranteed; however, interest accrues at a curtailed rate as specified in the programs. The carrying value of these loans is reduced based on an estimate of the expected cash flows discounted at the original note rate plus a liquidity spread. Guaranteed loans may be modified in TDRs in accordance with U.S. government agency guidelines. Interest continues to accrue based on the modified rate. Guaranteed loans may either be resold into GNMA pools after a performance period specified by the programs or foreclosed and conveyed to the guarantors.

Loans are disaggregated into portfolio segments and further disaggregated into classes. The portfolio segment is the level at which the Company develops and documents a systematic method for determining its allowance for credit losses. Classes are a further disaggregation of portfolio segments based on the risk characteristics of the loans and the Company’s method for monitoring and assessing credit risk.

Portfolio segments of the loan portfolio are as follows (in thousands):



	June 30, 2017								December 31, 2016
	Fixed Rate		Variable Rate		Non-accrual		Total		Fixed Rate		Variable Rate		Non-accrual		Total
Commercial	$	2,198,066	$	8,242,732	$	197,157	$	10,637,955	$	2,327,085	$	7,884,786	$	178,953	$	10,390,824
Commercial real estate	594,542		3,090,275		3,775		3,688,592		624,187		3,179,338		5,521		3,809,046
Residential mortgage	1,597,587		297,376		44,235		1,939,198		1,647,357		256,255		46,220		1,949,832
Personal	150,728		766,900		272		917,900		154,971		684,697		290		839,958
Total	$	4,540,923	$	12,397,283	$	245,439	$	17,183,645	$	4,753,600	$	12,005,076	$	230,984	$	16,989,660
Accruing loans past due (90 days)¹							$	1,414							$	5



	June 30, 2016
	Fixed Rate		Variable Rate		Non-accrual		Total
Commercial	$	1,994,415	$	8,180,033	$	181,989	$	10,356,437
Commercial real estate	612,822		2,961,364		7,780		3,581,966
Residential mortgage	1,586,116		237,746		57,061		1,880,923
Personal	109,447		477,622		354		587,423
Total	$	4,302,800	$	11,856,765	$	247,184	$	16,406,749
Accruing loans past due (90 days)¹							$	2,899


¹	Excludes residential mortgage loans guaranteed by agencies of the U.S. government

At June 30, 2017, $5.7 billion or 33 percent of our total loan portfolio is to businesses and individuals attributed to the Texas market and $3.4 billion or 20 percent of the total loan portfolio is to businesses and individuals attributed to the Oklahoma market. These geographic concentrations subject the loan portfolio to the general economic conditions within these areas.

Commercial

Commercial loans represent loans for working capital, facilities acquisition or expansion, purchases of equipment and other needs of commercial customers primarily located within our geographical footprint. Commercial loans are underwritten individually and represent ongoing relationships based on a thorough knowledge of the customer, the customer’s industry and market. While commercial loans are generally secured by the customer’s assets including real property, inventory, accounts receivable, operating equipment, interest in mineral rights and other property and may also include personal guarantees of the owners and related parties, the primary source of repayment of the loans is the ongoing cash flow from operations of the customer’s business. Inherent lending risk is centrally monitored on a continuous basis from underwriting throughout the life of the loan for compliance with commercial lending policies.

At June 30, 2017, commercial loans attributed to the Texas market totaled $3.6 billion or 33 percent of the commercial loan portfolio segment and commercial loans attributed to the Oklahoma market totaled $2.1 billion or 19 percent of the commercial loan portfolio segment.

The commercial loan portfolio segment is further divided into loan classes. The energy loan class totaled $2.8 billion or 17 percent of total loans at June 30, 2017, including $2.4 billion of outstanding loans to energy producers. Approximately 58 percent of committed production loans are secured by properties primarily producing oil and 42 percent are secured by properties producing natural gas. The services loan class totaled $3.0 billion or 17 percent of total loans at June 30, 2017. Approximately $1.5 billion of loans in the services category consist of loans with individual balances of less than $10 million. Businesses included in the services class include governmental, finance and insurance, not-for-profit, educational services and loans to entities providing services for real estate and construction. The healthcare loan class totaled $2.2 billion or 13 percent of total loans at June 30, 2017. The healthcare loan class consists primarily of loans for the development and operation of senior housing and care facilities, including independent living, assisted living and skilled nursing. Healthcare also includes loans to hospitals and other medical service providers.

Commercial Real Estate

Commercial real estate loans are for the construction of buildings or other improvements to real estate and property held by borrowers for investment purposes primarily within our geographical footprint. We require collateral values in excess of the loan amounts, demonstrated cash flows in excess of expected debt service requirements, equity investment in the project and a portion of the project already sold, leased or permanent financing already secured. The expected cash flows from all significant new or renewed income producing property commitments are stress tested to reflect the risks in varying interest rates, vacancy rates and rental rates. As with commercial loans, inherent lending risks are centrally monitored on a continuous basis from underwriting throughout the life of the loan for compliance with applicable lending policies.

At June 30, 2017, 32 percent of commercial real estate loans are secured by properties primarily located in the Dallas and Houston areas of Texas. An additional 12 percent of commercial real estate loans are secured by properties located primarily in the Tulsa and Oklahoma City metropolitan areas of Oklahoma.

Residential Mortgage and Personal

Residential mortgage loans provide funds for our customers to purchase or refinance their primary residence or to borrow against the equity in their home. Residential mortgage loans are secured by a first or second mortgage on the customer’s primary residence. Personal loans consist primarily of loans secured by the cash surrender value of insurance policies and marketable securities. It also includes direct loans secured by and for the purchase of automobiles, recreational and marine equipment as well as unsecured loans. Residential mortgage and personal loans are made in accordance with underwriting policies we believe to be conservative and are fully documented. Loans may be individually underwritten or credit scored based on size and other criteria. Credit scoring is assessed based on significant credit characteristics including credit history, residential and employment stability. Residential mortgage loans retained in the Company’s portfolio are primarily composed of various mortgage programs to support customer relationships including jumbo mortgage loans, non-builder construction loans and special loan programs for high net worth individuals and certain professionals. Jumbo loans may be fixed or variable rate and are fully amortizing. Jumbo loans generally conform to government sponsored entity standards, except that the loan size exceeds maximums required under these standards. These loans generally require a minimum FICO score of 720 and a maximum debt-to-income ratio (“DTI”) of 38 percent. Loan-to-value (“LTV”) ratios are tiered from 60 percent to 100 percent, depending on the market. Special mortgage programs include fixed and variable fully amortizing loans tailored to the needs of certain healthcare professionals. Variable rate loans are fully indexed at origination and may have fixed rates for three to ten years, then adjust annually thereafter.

At June 30, 2017, residential mortgage loans included $192 million of loans guaranteed by U.S. government agencies previously sold into GNMA mortgage pools. These loans either have been repurchased or are eligible to be repurchased by the Company when certain defined delinquency criteria are met. Although payments on these loans generally are past due more than 90 days, interest continues to accrue based on the government guarantee.

Home equity loans totaled $758 million at June 30, 2017. Approximately 65 percent of the home equity loan portfolio is comprised of first lien loans and 35 percent of the home equity portfolio is comprised of junior lien loans. Junior lien loans are distributed 49 percent to amortizing term loans and 51 percent to revolving lines of credit. Home equity loans generally require a minimum FICO score of 700 and a maximum DTI of 40 percent. The maximum loan amount available for our home equity loan products is generally $400 thousand. Revolving loans have a 5 year revolving period followed by a 15 year term of amortizing repayments. Interest-only home equity loans may not be extended for any additional revolving time. All other home equity loans may be extended at management's discretion for an additional 5 year revolving term, subject to an update of certain credit information.

Credit Commitments

Commitments to extend credit are agreements to lend to a customer as long as there is no violation of conditions established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. At June 30, 2017, outstanding commitments totaled $9.6 billion. Because some commitments are expected to expire before being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. BOK Financial uses the same credit policies in making commitments as it does loans.

The amount of collateral obtained, if deemed necessary, is based upon management’s credit evaluation of the borrower.

Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Because the credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan commitments, BOK Financial uses the same credit policies in evaluating the creditworthiness of the customer. Additionally, BOK Financial uses the same evaluation process in obtaining collateral on standby letters of credit as it does for loan commitments. The term of these standby letters of credit is defined in each commitment and typically corresponds with the underlying loan commitment. At June 30, 2017, outstanding standby letters of credit totaled $615 million. Commercial letters of credit are used to facilitate customer trade transactions with the drafts being drawn when the underlying transaction is consummated. At June 30, 2017, outstanding commercial letters of credit totaled $3.2 million.

Allowances for Credit Losses

BOK Financial maintains an allowance for loan losses and an accrual for off-balance sheet credit risk. The accrual for off-balance sheet credit risk is maintained at a level that is appropriate to cover estimated losses associated with credit instruments that are not currently recognized as assets such as loan commitments, standby letters of credit or guarantees. As discussed in greater detail in Note 6, the Company also has separate accruals for off-balance sheet credit risk related to residential mortgage loans previously sold with full or partial recourse and for residential mortgage loans sold to government sponsored agencies under standard representations and warranties.

The appropriateness of the allowance for loan losses and accrual for off-balance sheet credit losses (collectively "allowance for credit losses") is assessed by management based on an ongoing quarterly evaluation of the probable estimated losses inherent in the portfolio, including probable losses on both outstanding loans and unused commitments.

The allowance for loan losses consists of specific allowances attributed to impaired loans that have not yet been charged down to amounts we expect to recover, general allowances for unimpaired loans based on estimated loss rates by loan class and nonspecific allowances based on general economic conditions, risk concentration and related factors. There have been no material changes in the approach or techniques utilized in developing the allowance for loan losses and the accrual for off-balance sheet credit losses for the three and six months ended June 30, 2017.

Loans are considered to be impaired when it becomes probable that BOK Financial will be unable to collect all amounts due according to the contractual terms of the loan agreements. Internally risk graded loans are evaluated individually for impairment. Substantially all commercial and commercial real estate loans and certain residential mortgage and consumer loans are risk graded based on evaluation of the borrowers' ability to repay. Certain commercial loans and most residential mortgage and consumer loans are small balance, homogeneous pools of loans that are not risk graded. Non-risk graded loans are identified as impaired based on performance status. Generally, non-risk graded loans 90 days or more past due or modified in a TDR or in bankruptcy are considered to be impaired.

Specific allowances for impaired loans are measured by an evaluation of estimated future cash flows discounted at the loans’ initial effective interest rate or the fair value of collateral for certain collateral dependent loans. Collateral value of real property is generally based on third party appraisals that conform to Uniform Standards of Professional Appraisal Practice, less estimated selling costs. Appraised values are on an "as-is" basis and are generally not adjusted by the Company. Updated appraisals are obtained at least annually or more frequently if market conditions indicate collateral values have declined. Collateral value of mineral rights is generally determined by our internal staff of engineers based on projected cash flows under current market conditions. Collateral values and available cash resources that support impaired loans are evaluated quarterly. Historical statistics may be used as a practical way to estimate impairment in limited situations, such as when a collateral dependent loan is identified as impaired at the end of a reporting period, until an updated appraisal of collateral value is received or a full assessment of future cash flows is completed. Estimates of future cash flows and collateral values require significant judgments and may be volatile.

General allowances for unimpaired loans are based on estimated loss rates by loan class. The gross loss rate for each loan class is determined by the greater of the current gross loss rate based on the most recent twelve months or a ten-year gross loss rate. Recoveries are not directly considered in the estimation of loss rates. Recoveries generally do not follow predictable patterns and are not received until well after the charge-off date as a result of protracted legal actions. For risk graded loans, gross loss rates are adjusted for changes in risk grading. For each loan class, the current weighted average risk grade is compared to the long-term average risk grade. This comparison determines whether credit risk in each loan class is increasing or decreasing. Loss rates are adjusted upward or downward in proportion to changes in average risk grading. General allowances for unimpaired loans also consider inherent risks identified for each loan class. Inherent risks consider loss rates that most appropriately represent the current credit cycle and other factors attributable to specific loan classes which have not yet been represented in the gross loss rates or risk grading. These factors include changes in commodity prices or engineering imprecision, which may affect the value of reserves that secure our energy loan portfolio, construction risk that may affect commercial real estate loans, changes in regulations and public policy that may disproportionately impact health care loans and changes in loan products.

Nonspecific allowances are maintained for risks beyond factors specific to a particular loan or loan class. These factors include trends in the economy of our primary lending areas, concentrations in large balance loans and other relevant factors.

An accrual for off-balance sheet credit losses is included in Other liabilities in the Consolidated Balance Sheets. The appropriateness of this accrual is determined in the same manner as the allowance for loan losses.

A provision for credit losses is charged against or credited to earnings in amounts necessary to maintain an appropriate allowance for credit losses. Recoveries of loans previously charged off are added to the allowance when received.

The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit for the three months ended June 30, 2017 is summarized as follows (in thousands):



	Commercial			Commercial Real Estate			Residential Mortgage			Personal			Nonspecific Allowance		Total
Allowance for loan losses:
Beginning balance	$	137,616		$	58,343		$	18,177		$	7,247		$	27,327	$	248,710
Provision for loan losses	1,546			105			(47		)	1,358			47		3,009
Loans charged off	(1,703		)	(76		)	(40		)	(1,053		)	—		(2,872		)
Recoveries	283			208			169			554			—		1,214
Ending balance	$	137,742		$	58,580		$	18,259		$	8,106		$	27,374	$	250,061
Allowance for off-balance sheet credit losses:
Beginning balance	$	9,288		$	106		$	40		$	6		$	—	$	9,440
Provision for off-balance sheet credit losses	(2,987		)	(22		)	(2		)	2			—		(3,009		)
Ending balance	$	6,301		$	84		$	38		$	8		$	—	$	6,431

Total provision for credit losses	$	(1,441	)	$	83		$	(49	)	$	1,360		$	47	$	—

The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit for the six months ended June 30, 2017 is summarized as follows (in thousands):



	Commercial			Commercial Real Estate			Residential Mortgage			Personal			Nonspecific Allowance			Total
Allowance for loan losses:
Beginning balance	$	140,213		$	50,749		$	18,224		$	8,773		$	28,200		$	246,159
Provision for loan losses	(1,809		)	6,964			(86		)	570			(826		)	4,813
Loans charged off	(2,127		)	(76		)	(276		)	(2,546		)	—			(5,025		)
Recoveries	1,465			943			397			1,309			—			4,114
Ending balance	$	137,742		$	58,580		$	18,259		$	8,106		$	27,374		$	250,061
Allowance for off-balance sheet credit losses:
Beginning balance	$	11,063		$	123		$	50		$	8		$	—		$	11,244
Provision for off-balance sheet credit losses	(4,762		)	(39		)	(12		)	—			—			(4,813		)
Ending balance	$	6,301		$	84		$	38		$	8		$	—		$	6,431

Total provision for credit losses	$	(6,571	)	$	6,925		$	(98	)	$	570		$	(826	)	$	—



	Commercial			Commercial Real Estate			Residential Mortgage			Personal			Nonspecific Allowance		Total
Allowance for loan losses:
Beginning balance	$	139,793		$	44,453		$	18,467		$	5,022		$	25,421	$	233,156
Provision for loan losses	12,478			2,010			368			1,443			1,263		17,562
Loans charged off	(7,355		)	—			(345		)	(1,145		)	—		(8,845		)
Recoveries	223			282			200			681			—		1,386
Ending balance	$	145,139		$	46,745		$	18,690		$	6,001		$	26,684	$	243,259
Allowance for off-balance sheet credit losses:
Beginning balance	$	6,319		$	228		$	58		$	2		$	—	$	6,607
Provision for off-balance sheet credit losses	2,433			(25		)	4			26			—		2,438
Ending balance	$	8,752		$	203		$	62		$	28		$	—	$	9,045

Total provision for credit losses	$	14,911		$	1,985		$	372		$	1,469		$	1,263	$	20,000



	Commercial			Commercial Real Estate		Residential Mortgage			Personal			Nonspecific Allowance			Total
Allowance for loan losses:
Beginning balance	$	130,334		$	41,391	$	19,509		$	4,164		$	30,126		$	225,524
Provision for loan losses	43,575			4,987		(363		)	2,909			(3,442		)	47,666
Loans charged off	(29,481		)	—		(819		)	(2,536		)	—			(32,836		)
Recoveries	711			367		363			1,464			—			2,905
Ending balance	$	145,139		$	46,745	$	18,690		$	6,001		$	26,684		$	243,259
Allowance for off-balance sheet credit losses:
Beginning balance	$	1,506		$	153	$	30		$	22		$	—		$	1,711
Provision for off-balance sheet credit losses	7,246			50		32			6			—			7,334
Ending balance	$	8,752		$	203	$	62		$	28		$	—		$	9,045

Total provision for credit losses	$	50,821		$	5,037	$	(331	)	$	2,915		$	(3,442	)	$	55,000

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at June 30, 2017 is as follows (in thousands):



	Collectively Measured for Impairment				Individually Measured for Impairment				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,440,798	$	128,049	$	197,157	$	9,693	$	10,637,955	$	137,742
Commercial real estate	3,684,817		58,580		3,775		—		3,688,592		58,580
Residential mortgage	1,894,963		18,259		44,235		—		1,939,198		18,259
Personal	917,628		8,106		272		—		917,900		8,106
Total	16,938,206		212,994		245,439		9,693		17,183,645		222,687

Nonspecific allowance	—		—		—		—		—		27,374

Total	$	16,938,206	$	212,994	$	245,439	$	9,693	$	17,183,645	$	250,061

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2016 is as follows (in thousands):



	Collectively Measured for Impairment				Individually Measured for Impairment				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,211,871	$	139,416	$	178,953	$	797	$	10,390,824	$	140,213
Commercial real estate	3,803,525		50,749		5,521		—		3,809,046		50,749
Residential mortgage	1,903,612		18,178		46,220		46		1,949,832		18,224
Personal	839,668		8,773		290		—		839,958		8,773
Total	16,758,676		217,116		230,984		843		16,989,660		217,959

Nonspecific allowance	—		—		—		—		—		28,200

Total	$	16,758,676	$	217,116	$	230,984	$	843	$	16,989,660	$	246,159

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at June 30, 2016 is as follows (in thousands):



	Collectively Measured for Impairment				Individually Measured for Impairment				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,174,448	$	140,911	$	181,989	$	4,228	$	10,356,437	$	145,139
Commercial real estate	3,574,186		46,727		7,780		18		3,581,966		46,745
Residential mortgage	1,823,862		18,626		57,061		64		1,880,923		18,690
Personal	587,069		6,001		354		—		587,423		6,001
Total	16,159,565		212,265		247,184		4,310		16,406,749		216,575

Nonspecific allowance	—		—		—		—		—		26,684

Total	$	16,159,565	$	212,265	$	247,184	$	4,310	$	16,406,749	$	243,259

Credit Quality Indicators

The Company utilizes loan class and risk grading as primary credit quality indicators. Substantially all commercial and commercial real estate loans and certain residential mortgage and consumer loans are risk graded based on a quarterly evaluation of the borrowers’ ability to repay the loans. Certain commercial loans and most residential mortgage and consumer loans are small, homogeneous pools that are not risk graded.

The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans at June 30, 2017 is as follows (in thousands):



	Internally Risk Graded				Non-Graded				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,612,477	$	136,819	$	25,478	$	923	$	10,637,955	$	137,742
Commercial real estate	3,688,592		58,580		—		—		3,688,592		58,580
Residential mortgage	216,007		2,976		1,723,191		15,283		1,939,198		18,259
Personal	824,318		5,742		93,582		2,364		917,900		8,106
Total	15,341,394		204,117		1,842,251		18,570		17,183,645		222,687

Nonspecific allowance	—		—		—		—		—		27,374

Total	$	15,341,394	$	204,117	$	1,842,251	$	18,570	$	17,183,645	$	250,061

The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans at December 31, 2016 is as follows (in thousands):



	Internally Risk Graded				Non-Graded				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,360,725	$	139,293	$	30,099	$	920	$	10,390,824	$	140,213
Commercial real estate	3,809,046		50,749		—		—		3,809,046		50,749
Residential mortgage	243,703		2,893		1,706,129		15,331		1,949,832		18,224
Personal	744,602		5,035		95,356		3,738		839,958		8,773
Total	15,158,076		197,970		1,831,584		19,989		16,989,660		217,959

Nonspecific allowance	—		—		—		—		—		28,200

Total	$	15,158,076	$	197,970	$	1,831,584	$	19,989	$	16,989,660	$	246,159

The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans at June 30, 2016 is as follows (in thousands):



	Internally Risk Graded				Non-Graded				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,331,701	$	144,217	$	24,736	$	922	$	10,356,437	$	145,139
Commercial real estate	3,581,966		46,745		—		—		3,581,966		46,745
Residential mortgage	202,520		2,995		1,678,403		15,695		1,880,923		18,690
Personal	500,240		3,624		87,183		2,377		587,423		6,001
Total	14,616,427		197,581		1,790,322		18,994		16,406,749		216,575

Nonspecific allowance	—		—		—		—		—		26,684

Total	$	14,616,427	$	197,581	$	1,790,322	$	18,994	$	16,406,749	$	243,259

Loans are considered to be performing if they are in compliance with the original terms of the agreement and currently exhibit no factors that cause management to have doubts about the borrowers' ability to remain in compliance with the original terms of the agreement, which is consistent with the regulatory guideline of “pass.” Performing loans also include past due residential mortgages that are guaranteed by agencies of the U.S. government that continue to accrue interest based on criteria of the guarantors' programs. Other loans especially mentioned are currently performing in compliance with the original terms of the agreement but may have a potential weakness that deserves management’s close attention, consistent with regulatory guidelines.

The risk grading process identified certain loans that have a well-defined weakness (e.g. inadequate debt service coverage or liquidity or marginal capitalization; repayment may depend on collateral or other risk mitigation) that may jeopardize liquidation of the debt and represent a greater risk due to deterioration in the financial condition of the borrower. This is consistent with the regulatory guideline for “substandard.” Because the borrowers are still performing in accordance with the original terms of the loan agreements, these loans were not placed in nonaccruing status.

Nonaccruing loans represent loans for which full collection of principal and interest is uncertain. This is substantially the same criteria used to determine whether a loan is impaired and includes certain loans considered “substandard” and all loans considered “doubtful” by regulatory guidelines.

The following table summarizes the Company’s loan portfolio at June 30, 2017 by the risk grade categories (in thousands):



	Internally Risk Graded								Non-Graded
	Performing
	Pass		Other Loans Especially Mentioned		Accruing Substandard		Nonaccrual		Performing		Nonaccrual		Total
Commercial:
Energy	$	2,376,368	$	120,473	$	226,407	$	123,992	$	—	$	—	$	2,847,240
Services	2,921,510		12,452		17,111		7,754		—		—		2,958,827
Wholesale/retail	1,507,063		16,224		9,788		10,620		—		—		1,543,695
Manufacturing	513,442		6,540		16,499		9,656		—		—		546,137
Healthcare	2,130,339		33,554		33,120		24,505		—		—		2,221,518
Other commercial and industrial	453,712		2,961		17,861		20,526		25,374		104		520,538
Total commercial	9,902,434		192,204		320,786		197,053		25,374		104		10,637,955

Commercial real estate:
Residential construction and land development	138,790		—		751		2,051		—		—		141,592
Retail	720,730		1,774		—		301		—		—		722,805
Office	859,722		2,855		—		396		—		—		862,973
Multifamily	947,950		—		4,420		10		—		—		952,380
Industrial	693,635		—		—		—		—		—		693,635
Other commercial real estate	314,187		—		3		1,017		—		—		315,207
Total commercial real estate	3,675,014		4,629		5,174		3,775		—		—		3,688,592

Residential mortgage:
Permanent mortgage	212,563		1,693		478		1,273		750,891		22,142		989,040
Permanent mortgages guaranteed by U.S. government agencies	—		—		—		—		182,677		9,052		191,729
Home equity	—		—		—		—		746,661		11,768		758,429
Total residential mortgage	212,563		1,693		478		1,273		1,680,229		42,962		1,939,198

Personal	823,304		49		877		88		93,398		184		917,900

Total	$	14,613,315	$	198,575	$	327,315	$	202,189	$	1,799,001	$	43,250	$	17,183,645

The following table summarizes the Company’s loan portfolio at December 31, 2016 by the risk grade categories (in thousands):



	Internally Risk Graded								Non-Graded
	Performing
	Pass		Other Loans Especially Mentioned		Accruing Substandard		Nonaccrual		Performing		Nonaccrual		Total
Commercial:
Energy	$	1,937,790	$	119,583	$	307,996	$	132,499	$	—	$	—	$	2,497,868
Services	3,052,002		10,960		37,855		8,173		—		—		3,108,990
Wholesale/retail	1,535,463		16,886		13,062		11,407		—		—		1,576,818
Manufacturing	468,314		26,532		15,198		4,931		—		—		514,975
Healthcare	2,140,458		44,472		16,161		825		—		—		2,201,916
Other commercial and industrial	433,789		5,309		—		21,060		30,041		58		490,257
Total commercial	9,567,816		223,742		390,272		178,895		30,041		58		10,390,824

Commercial real estate:
Residential construction and land development	131,630		—		470		3,433		—		—		135,533
Retail	756,418		4,745		399		326		—		—		761,888
Office	798,462		—		—		426		—		—		798,888
Multifamily	898,800		—		4,434		38		—		—		903,272
Industrial	871,673		—		—		76		—		—		871,749
Other commercial real estate	336,488		—		6		1,222		—		—		337,716
Total commercial real estate	3,793,471		4,745		5,309		5,521		—		—		3,809,046

Residential mortgage:
Permanent mortgage	238,769		1,186		2,331		1,417		741,679		21,438		1,006,820
Permanent mortgages guaranteed by U.S. government agencies	—		—		—		—		187,541		11,846		199,387
Home equity	—		—		—		—		732,106		11,519		743,625
Total residential mortgage	238,769		1,186		2,331		1,417		1,661,326		44,803		1,949,832

Personal	743,451		—		1,054		97		95,163		193		839,958

Total	$	14,343,507	$	229,673	$	398,966	$	185,930	$	1,786,530	$	45,054	$	16,989,660

The following table summarizes the Company’s loan portfolio at June 30, 2016 by the risk grade categories (in thousands):



	Internally Risk Graded								Non-Graded
	Performing
	Pass		Other Loans Especially Mentioned		Accruing Substandard		Nonaccrual		Performing		Nonaccrual		Total
Commercial:
Energy	$	2,031,955	$	197,531	$	421,025	$	168,145	$	—	$	—	$	2,818,656
Services	2,805,307		6,253		9,916		9,388		—		—		2,830,864
Wholesale/retail	1,478,966		24,595		26,624		2,772		—		—		1,532,957
Manufacturing	556,741		18,757		19,612		293		—		—		595,403
Healthcare	2,011,934		29,420		8,917		875		—		—		2,051,146
Other commercial and industrial	478,169		24,053		—		453		24,673		63		527,411
Total commercial	9,363,072		300,609		486,094		181,926		24,673		63		10,356,437

Commercial real estate:
Residential construction and land development	152,343		—		972		4,261		—		—		157,576
Retail	787,779		5,962		413		1,265		—		—		795,419
Office	767,296		906		304		606		—		—		769,112
Multifamily	781,058		—		6,077		65		—		—		787,200
Industrial	645,510		—		—		76		—		—		645,586
Other commercial real estate	425,558		—		8		1,507		—		—		427,073
Total commercial real estate	3,559,544		6,868		7,774		7,780		—		—		3,581,966

Residential mortgage:
Permanent mortgage	194,962		1,197		3,406		2,955		742,214		24,273		969,007
Permanent mortgages guaranteed by U.S. government agencies	—		—		—		—		172,991		19,741		192,732
Home equity	—		—		—		—		709,092		10,092		719,184
Total residential mortgage	194,962		1,197		3,406		2,955		1,624,297		54,106		1,880,923

Personal	496,534		—		3,590		116		86,945		238		587,423

Total	$	13,614,112	$	308,674	$	500,864	$	192,777	$	1,735,915	$	54,407	$	16,406,749

Impaired Loans

Loans are considered to be impaired when it is probable that the Company will not be able to collect all amounts due according to the contractual terms of the loan agreement. This includes all nonaccruing loans, all loans modified in a TDR and all loans repurchased from GNMA pools.

A summary of impaired loans follows (in thousands):



	As of										For the				For the
	June 30, 2017										Three Months Ended				Six Months Ended
			Recorded Investment								June 30, 2017				June 30, 2017
	Unpaid Principal Balance		Total		With No Allowance		With Allowance		Related Allowance		Average Recorded Investment		Interest Income Recognized		Average Recorded Investment		Interest Income Recognized
Commercial:
Energy	$	141,091	$	123,992	$	56,988	$	67,004	$	8,874	$	117,209	$	—	$	128,246	$	—
Services	11,209		7,754		7,754		—		—		7,734		—		7,964		—
Wholesale/retail	17,392		10,620		10,620		—		—		10,855		—		11,013		—
Manufacturing	10,223		9,656		9,656		—		—		7,781		—		7,293		—
Healthcare	24,795		24,505		18,883		5,622		802		12,707		—		12,665		—
Other commercial and industrial	28,933		20,630		20,609		21		17		20,706		—		20,874		—
Total commercial	233,643		197,157		124,510		72,647		9,693		176,992		—		188,055		—

Commercial real estate:
Residential construction and land development	3,676		2,051		2,051		—		—		2,334		—		2,742		—
Retail	518		301		301		—		—		308		—		314		—
Office	499		396		396		—		—		404		—		411		—
Multifamily	1,000		10		10		—		—		17		—		24		—
Industrial	—		—		—		—		—		38		—		38		—
Other commercial real estate	1,212		1,017		1,017		—		—		1,024		—		1,119		—
Total commercial real estate	6,905		3,775		3,775		—		—		4,125		—		4,648		—

Residential mortgage:
Permanent mortgage	28,603		23,415		23,415		—		—		23,801		307		23,135		598
Permanent mortgage guaranteed by U.S. government agencies¹	197,659		191,729		191,729		—		—		202,946		2,021		205,159		3,925
Home equity	13,064		11,768		11,768		—		—		11,776		—		11,643		—
Total residential mortgage	239,326		226,912		226,912		—		—		238,523		2,328		239,937		4,523

Personal	307		272		272		—		—		253		—		281		—

Total	$	480,181	$	428,116	$	355,469	$	72,647	$	9,693	$	419,893	$	2,328	$	432,921	$	4,523


¹	All permanent mortgage loans guaranteed by U.S. government agencies are considered impaired as we do not expect full collection of contractual principal and interest. At June 30, 2017, $9.1 million of these loans were nonaccruing and $183 million were accruing based on the guarantee by U.S. government agencies.

Generally, no interest income is recognized on impaired loans until all principal balances, including amounts charged-off, are recovered.

A summary of impaired loans at December 31, 2016 follows (in thousands):



			Recorded Investment
	Unpaid Principal Balance		Total		With No Allowance		With Allowance		Related Allowance
Commercial:
Energy	$	146,897	$	132,499	$	121,418	$	11,081	$	762
Services	11,723		8,173		8,173		—		—
Wholesale/retail	17,669		11,407		11,407		—		—
Manufacturing	5,320		4,931		4,931		—		—
Healthcare	1,147		825		825		—		—
Other commercial and industrial	29,006		21,118		21,083		35		35
Total commercial	211,762		178,953		167,837		11,116		797

Commercial real estate:
Residential construction and land development	4,951		3,433		3,433		—		—
Retail	530		326		326		—		—
Office	521		426		426		—		—
Multifamily	1,000		38		38		—		—
Industrial	76		76		76		—		—
Other commercial real estate	7,349		1,222		1,222		—		—
Total commercial real estate	14,427		5,521		5,521		—		—

Residential mortgage:
Permanent mortgage	28,830		22,855		22,809		46		46
Permanent mortgage guaranteed by U.S. government agencies¹	205,564		199,387		199,387		—		—
Home equity	12,611		11,519		11,519		—		—
Total residential mortgage	247,005		233,761		233,715		46		46

Personal	332		290		290		—		—

Total	$	473,526	$	418,525	$	407,363	$	11,162	$	843


¹	All permanent mortgage loans guaranteed by U.S. government agencies are considered impaired as we do not expect full collection of contractual principal and interest. At December 31, 2016, $12 million of these loans were nonaccruing and $188 million were accruing based on the guarantee by U.S. government agencies.

A summary of impaired loans at June 30, 2016 follows (in thousands):



											For the				For the
	As of June 30, 2016										Three Months Ended				Six Months Ended
			Recorded Investment								June 30, 2016				June 30, 2016
	Unpaid Principal Balance		Total		With No Allowance		With Allowance		Related Allowance		Average Recorded Investment		Interest Income Recognized		Average Recorded Investment		Interest Income Recognized
Commercial:
Energy	$	202,369	$	168,145	$	136,264	$	31,881	$	4,228	$	163,849	$	—	$	97,923	$	—
Services	12,780		9,388		9,388		—		—		9,450		—		9,839		—
Wholesale/retail	8,697		2,772		2,772		—		—		3,229		—		2,846		—
Manufacturing	650		293		293		—		—		303		—		312		—
Healthcare	1,175		875		875		—		—		949		—		973		—
Other commercial and industrial	8,186		516		516		—		—		542		—		569		—
Total commercial	233,857		181,989		150,108		31,881		4,228		178,322		—		112,462		—

Commercial real estate:
Residential construction and land development	7,177		4,261		4,261		—		—		4,525		—		4,335		—
Retail	1,914		1,265		1,265		—		—		1,283		—		1,292		—
Office	907		606		606		—		—		618		—		628		—
Multifamily	1,000		65		65		—		—		157		—		169		—
Industrial	76		76		76		—		—		76		—		76		—
Other commercial real estate	7,445		1,507		1,355		152		18		1,865		—		1,890		—
Total commercial real estate	18,519		7,780		7,628		152		18		8,524		—		8,390		—

Residential mortgage:
Permanent mortgage	33,793		27,228		27,117		111		64		27,362		304		28,106		631
Permanent mortgage guaranteed by U.S. government agencies¹	198,534		192,732		192,732		—		—		191,430		2,023		195,563		3,795
Home equity	10,964		10,092		10,092		—		—		10,311		—		10,224		—
Total residential mortgage	243,291		230,052		229,941		111		64		229,103		2,327		233,893		4,426

Personal	1,174		354		354		—		—		342		—		409		—

Total	$	496,841	$	420,175	$	388,031	$	32,144	$	4,310	$	416,291	$	2,327	$	355,154	$	4,426


¹	All permanent mortgage loans guaranteed by U.S. government agencies are considered impaired as we do not expect full collection of contractual principal and interest. At June 30, 2016, $20 million of these loans were nonaccruing and $173 million were accruing based on the guarantee by U.S. government agencies.

Troubled Debt Restructurings

A summary of troubled debt restructurings ("TDRs") by accruing status as of June 30, 2017 is as follows (in thousands):



	As of June 30, 2017								Amounts Charged Off During:
	Recorded Investment		Performing in Accordance With Modified Terms		Not Performing in Accordance With Modified Terms		Specific Allowance		Three Months Ended June 30, 2017		Six Months Ended June 30, 2017
Nonaccruing TDRs:

Commercial:
Energy	$	22,466	$	12,692	$	9,774	$	4,308	$	—	$	—
Services	7,208		6,561		647		—		3		3
Wholesale/retail	10,524		10,524		—		—		—		—
Manufacturing	195		195		—		—		—		—
Healthcare	—		—		—		—		—		—
Other commercial and industrial	20,531		35		20,496		—		—		—
Total commercial	60,924		30,007		30,917		4,308		3		3

Commercial real estate:
Residential construction and land development	381		145		236		—		—		—
Retail	301		301		—		—		—		—
Office	121		—		121		—		—		—
Multifamily	—		—		—		—		—		—
Industrial	—		—		—		—		—		—
Other commercial real estate	365		365		—		—		—		—
Total commercial real estate	1,168		811		357		—		—		—

Residential mortgage:
Permanent mortgage	14,284		9,939		4,345		—		—		—
Permanent mortgage guaranteed by U.S. government agencies	5,962		1,176		4,786		—		—		—
Home equity	5,549		4,239		1,310		—		—		31
Total residential mortgage	25,795		15,354		10,441		—		—		31

Personal	228		228		—		—		7		8

Total nonaccruing TDRs	$	88,115	$	46,400	$	41,715	$	4,308	$	10	$	42

Accruing TDRs:
Permanent mortgages guaranteed by U.S. government agencies	80,624		24,506		56,118		—		—		—

Total TDRs	$	168,739	$	70,906	$	97,833	$	4,308	$	10	$	42

A summary of troubled debt restructurings by accruing status as of December 31, 2016 is as follows (in thousands):



	As of
	December 31, 2016
	Recorded Investment		Performing in Accordance With Modified Terms		Not Performing in Accordance With Modified Terms		Specific Allowance
Nonaccruing TDRs:

Commercial:
Energy	$	16,893	$	10,867	$	6,026	$	—
Services	7,527		6,830		697		—
Wholesale/retail	11,291		11,251		40		—
Manufacturing	224		224		—		—
Healthcare	607		—		607		—
Other commercial and industrial	337		53		284		—
Total commercial	36,879		29,225		7,654		—

Commercial real estate:
Residential construction and land development	690		97		593		—
Retail	326		326		—		—
Office	143		143		—		—
Multifamily	—		—		—		—
Industrial	—		—		—		—
Other commercial real estate	548		548		—		—
Total commercial real estate	1,707		1,114		593		—

Residential mortgage:
Permanent mortgage	14,876		10,175		4,701		46
Permanent mortgage guaranteed by U.S. government agencies	6,702		2,241		4,461		—
Home equity	5,346		4,458		888		—
Total residential mortgage	26,924		16,874		10,050		46

Personal	237		236		1		—

Total nonaccuring TDRs	$	65,747	$	47,449	$	18,298	$	46

Accruing TDRs:
Permanent mortgages guaranteed by U.S. government agencies	81,370		27,289		54,081		—

Total TDRs	$	147,117	$	74,738	$	72,379	$	46

A summary of troubled debt restructurings by accruing status as of June 30, 2016 is as follows (in thousands):



	As of June 30, 2016								Amounts Charged Off During:
	Recorded Investment		Performing in Accordance With Modified Terms		Not Performing in Accordance With Modified Terms		Specific Allowance		Three Months Ended June 30, 2016		Six Months Ended June 30, 2016
Nonaccruing TDRs:

Commercial:
Energy	$	2,246	$	—	$	2,246	$	—	$	500	$	500
Services	8,610		7,853		757		—		—		—
Wholesale/retail	2,467		2,427		40		—		—		—
Manufacturing	253		253		—		—		—		—
Healthcare	640		640		—		—		—		—
Other commercial and industrial	516		63		453		—		—		57
Total commercial	14,732		11,236		3,496		—		500		557

Commercial real estate:
Residential construction and land development	1,601		1,079		522		—		—		—
Retail	1,264		907		357		—		—		—
Office	152		152		—		—		—		—
Multifamily	—		—		—		—		—		—
Industrial	—		—		—		—		—		—
Other commercial real estate	793		372		421		—		—		—
Total commercial real estate	3,810		2,510		1,300		—		—		—

Residential mortgage:
Permanent mortgage	17,367		12,462		4,905		64		37		52
Permanent mortgage guaranteed by U.S. government agencies	9,709		2,024		7,685		—		—		—
Home equity	4,763		4,139		624		—		60		126
Total residential mortgage	31,839		18,625		13,214		64		97		178

Personal	298		276		22		—		3		9

Total nonaccruing TDRs	$	50,679	$	32,647	$	18,032	$	64	$	600	$	744

Accruing TDRs:
Permanent mortgages guaranteed by U.S. government agencies	78,806		27,999		50,807		—		—		—

Total TDRs	$	129,485	$	60,646	$	68,839	$	64	$	600	$	744

Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following tables detail the recorded balance of loans at June 30, 2017 by class that were restructured during the three months ended June 30, 2017 by primary type of concession (in thousands):



	Three Months Ended June 30, 2017
	Accruing						Nonaccrual						Total
	Payment Stream		Combination & Other		Total		Payment Stream		Combination & Other		Total
Commercial:
Energy	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Services	—		—		—		—		—		—		—
Wholesale/retail	—		—		—		—		626		626		626
Manufacturing	—		—		—		—		—		—		—
Healthcare	—		—		—		—		—		—		—
Other commercial and industrial	—		—		—		20,242		—		20,242		20,242
Total commercial	—		—		—		20,242		626		20,868		20,868

Commercial real estate:
Residential construction and land development	—		—		—		—		—		—		—
Retail	—		—		—		—		—		—		—
Office	—		—		—		—		—		—		—
Multifamily	—		—		—		—		—		—		—
Industrial	—		—		—		—		—		—		—
Other commercial real estate	—		—		—		—		—		—		—
Total commercial real estate	—		—		—		—		—		—		—

Residential mortgage:
Permanent mortgage	—		—		—		138		53		191		191
Permanent mortgage guaranteed by U.S. government agencies	10,410		1,568		11,978		223		—		223		12,201
Home equity	—		—		—		26		559		585		585
Total residential mortgage	10,410		1,568		11,978		387		612		999		12,977

Personal	—		—		—		—		47		47		47

Total	$	10,410	$	1,568	$	11,978	$	20,629	$	1,285	$	21,914	$	33,892



	Six Months Ended June 30, 2017
	Accruing							Nonaccrual							Total
		Payment Stream		Combination & Other		Total			Payment Stream		Combination & Other		Total
Commercial:
Energy		$	—	$	—	$	—		$	13,010	$	—	$	13,010	$	13,010
Services		—		—		—			—		—		—		—
Wholesale/retail		—		—		—			—		626		626		626
Manufacturing		—		—		—			—		—		—		—
Healthcare		—		—		—			—		—		—		—
Other commercial and industrial		—		—		—			20,242		—		20,242		20,242
Total commercial		—		—		—			33,252		626		33,878		33,878

Commercial real estate:
Residential construction and land development		—		—		—			—		—		—		—
Retail		—		—		—			—		—		—		—
Office		—		—		—			—		—		—		—
Multifamily		—		—		—			—		—		—		—
Industrial		—		—		—			—		—		—		—
Other commercial real estate		—		—		—			—		—		—		—
Total commercial real estate		—		—		—			—		—		—		—

Residential mortgage:
Permanent mortgage		—		—		—			153		84		237		237
Permanent mortgage guaranteed by U.S. government agencies		14,883		2,586		17,469			224		85		309		17,778
Home equity		—		—		—			149		1,053		1,202		1,202
Total residential mortgage		14,883		2,586		17,469			526		1,222		1,748		19,217

Personal		—		—		—			—		51		51		51

Total		$	14,883	$	2,586	$	17,469		$	33,778	$	1,899	$	35,677	$	53,146

Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following tables detail the recorded balance of loans by class that were restructured during three months ended June 30, 2016 by primary type of concession (in thousands):



	Three Months Ended June 30, 2016
	Accruing						Nonaccrual						Total
	Payment Stream		Combination & Other		Total		Payment Stream		Combination & Other		Total
Commercial:
Energy	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Services	—		—		—		—		—		—		—
Wholesale/retail	—		—		—		—		—		—		—
Manufacturing	—		—		—		—		—		—		—
Healthcare	—		—		—		—		—		—		—
Other commercial and industrial	—		—		—		—		—		—		—
Total commercial	—		—		—		—		—		—		—

Commercial real estate:
Residential construction and land development	—		—		—		—		—		—		—
Retail	—		—		—		—		—		—		—
Office	—		—		—		—		—		—		—
Multifamily	—		—		—		—		—		—		—
Industrial	—		—		—		—		—		—		—
Other commercial real estate	—		—		—		—		—		—		—
Total commercial real estate	—		—		—		—		—		—		—

Residential mortgage:
Permanent mortgage	—		—		—		684		1,183		1,867		1,867
Permanent mortgage guaranteed by U.S. government agencies	2,783		4,455		7,238		—		625		625		7,863
Home equity	—		—		—		48		329		377		377
Total residential mortgage	2,783		4,455		7,238		732		2,137		2,869		10,107

Personal	—		—		—		—		65		65		65

Total	$	2,783	$	4,455	$	7,238	$	732	$	2,202	$	2,934	$	10,172



	Six Months Ended June 30, 2016
	Accruing						Nonaccrual						Total
	Payment Stream		Combination & Other		Total		Payment Stream		Combination & Other		Total
Commercial:
Energy	$	—	$	—	$	—	$	501	$	—	$	501	$	501
Services	—		—		—		—		—		—		—
Wholesale/retail	—		—		—		—		—		—		—
Manufacturing	—		—		—		—		—		—		—
Healthcare	—		—		—		—		—		—		—
Other commercial and industrial	—		—		—		—		—		—		—
Total commercial	—		—		—		501		—		501		501

Commercial real estate:
Residential construction and land development	—		—		—		—		—		—		—
Retail	—		—		—		—		—		—		—
Office	—		—		—		—		—		—		—
Multifamily	—		—		—		—		—		—		—
Industrial	—		—		—		—		—		—		—
Other commercial real estate	—		—		—		—		—		—		—
Total commercial real estate	—		—		—		—		—		—		—

Residential mortgage:
Permanent mortgage	—		—		—		1,046		1,244		2,290		2,290
Permanent mortgage guaranteed by U.S. government agencies	6,625		7,818		14,443		—		625		625		15,068
Home equity	—		—		—		48		791		839		839
Total residential mortgage	6,625		7,818		14,443		1,094		2,660		3,754		18,197

Personal	—		—		—		—		72		72		72

Total	$	6,625	$	7,818	$	14,443	$	1,595	$	2,732	$	4,327	$	18,770

The following table summarizes, by loan class, the recorded investment at June 30, 2017 and 2016, respectively, of loans modified as TDRs within the previous 12 months and for which there was a payment default during the three months ended June 30, 2017 and 2016, respectively (in thousands):



	Three Months Ended June 30, 2017						Six Months Ended June 30, 2017
	Accruing		Nonaccrual		Total		Accruing		Nonaccrual		Total
Commercial:
Energy	$	—	$	9,774	$	9,774	$	—	$	9,774	$	9,774
Services	—		—		—		—		—		—
Wholesale/retail	—		—		—		—		—		—
Manufacturing	—		—		—		—		—		—
Healthcare	—		—		—		—		—		—
Other commercial and industrial	—		20,242		20,242		—		20,242		20,242
Total commercial	—		30,016		30,016		—		30,016		30,016

Commercial real estate:
Residential construction and land development	—		—		—		—		—		—
Retail	—		—		—		—		—		—
Office	—		—		—		—		—		—
Multifamily	—		—		—		—		—		—
Industrial	—		—		—		—		—		—
Other commercial real estate	—		—		—		—		—		—
Total commercial real estate	—		—		—		—		—		—

Residential mortgage:
Permanent mortgage	—		161		161		—		161		161
Permanent mortgage guaranteed by U.S. government agencies	22,234		918		23,152		22,590		918		23,508
Home equity	—		1,113		1,113		—		1,262		1,262
Total residential mortgage	22,234		2,192		24,426		22,590		2,341		24,931

Personal	—		—		—		—		—		—

Total	$	22,234	$	32,208	$	54,442	$	22,590	$	32,357	$	54,947

A payment default is defined as being 30 days or more past due. The table above includes loans that experienced a payment default during the period, but may be performing in accordance with the modified terms as of the balance sheet date.



	Three Months Ended June 30, 2016						Six Months Ended June 30, 2016
	Accruing		Nonaccrual		Total		Accruing		Nonaccrual		Total
Commercial:
Energy	$	—	$	2,246	$	2,246	$	—	$	2,246	$	2,246
Services	—		—		—		—		—		—
Wholesale/retail	—		—		—		—		—		—
Manufacturing	—		—		—		—		—		—
Healthcare	—		—		—		—		—		—
Other commercial and industrial	—		—		—		—		—		—
Total commercial	—		2,246		2,246		—		2,246		2,246

Commercial real estate:
Residential construction and land development	—		—		—		—		—		—
Retail	—		—		—		—		—		—
Office	—		—		—		—		—		—
Multifamily	—		—		—		—		—		—
Industrial	—		—		—		—		—		—
Other commercial real estate	—		—		—		—		—		—
Total commercial real estate	—		—		—		—		—		—

Residential mortgage:
Permanent mortgage	—		788		788		—		1,806		1,806
Permanent mortgage guaranteed by U.S. government agencies	18,893		1,006		19,899		20,621		1,006		21,627
Home equity	—		232		232		—		232		232
Total residential mortgage	18,893		2,026		20,919		20,621		3,044		23,665

Personal	—		—		—		—		—		—

Total	$	18,893	$	4,272	$	23,165	$	20,621	$	5,290	$	25,911

Nonaccrual & Past Due Loans

Past due status for all loan classes is based on the actual number of days since the last payment was due according to the contractual terms of the loans.

A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of June 30, 2017 is as follows (in thousands):



			Past Due
	Current		30 to 59 Days		60 to 89 Days		90 Days or More		Nonaccrual		Total
Commercial:
Energy	$	2,723,248	$	—	$	—	$	—	$	123,992	$	2,847,240
Services	2,949,562		50		180		1,281		7,754		2,958,827
Wholesale/retail	1,532,986		89		—		—		10,620		1,543,695
Manufacturing	536,481		—		—		—		9,656		546,137
Healthcare	2,196,088		925		—		—		24,505		2,221,518
Other commercial and industrial	499,743		45		119		1		20,630		520,538
Total commercial	10,438,108		1,109		299		1,282		197,157		10,637,955

Commercial real estate:
Residential construction and land development	139,070		471		—		—		2,051		141,592
Retail	722,504		—		—		—		301		722,805
Office	862,577		—		—		—		396		862,973
Multifamily	952,370		—		—		—		10		952,380
Industrial	693,635		—		—		—		—		693,635
Other commercial real estate	314,187		3		—		—		1,017		315,207
Total commercial real estate	3,684,343		474		—		—		3,775		3,688,592

Residential mortgage:
Permanent mortgage	962,443		2,024		1,026		132		23,415		989,040
Permanent mortgages guaranteed by U.S. government agencies	36,867		18,416		13,581		113,813		9,052		191,729
Home equity	744,735		1,564		362		—		11,768		758,429
Total residential mortgage	1,744,045		22,004		14,969		113,945		44,235		1,939,198

Personal	916,852		487		289		—		272		917,900

Total	$	16,783,348	$	24,074	$	15,557	$	115,227	$	245,439	$	17,183,645

A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2016 is as follows (in thousands):



			Past Due
	Current		30 to 59 Days		60 to 89 Days	90 Days or More		Nonaccrual		Total
Commercial:
Energy	$	2,364,890	$	479	—	$	—	$	132,499	$	2,497,868
Services	3,099,605		191		1,021	—		8,173		3,108,990
Wholesale/retail	1,561,650		3,761		—	—		11,407		1,576,818
Manufacturing	509,662		382		—	—		4,931		514,975
Healthcare	2,201,050		—		41	—		825		2,201,916
Other commercial and industrial	468,981		155		3	—		21,118		490,257
Total commercial	10,205,838		4,968		1,065	—		178,953		10,390,824

Commercial real estate:
Residential construction and land development	132,100		—		—	—		3,433		135,533
Retail	761,562		—		—	—		326		761,888
Office	798,462		—		—	—		426		798,888
Multifamily	903,234		—		—	—		38		903,272
Industrial	871,673		—		—	—		76		871,749
Other commercial real estate	336,488		6		—	—		1,222		337,716
Total commercial real estate	3,803,519		6		—	—		5,521		3,809,046

Residential mortgage:
Permanent mortgage	979,386		3,299		1,280	—		22,855		1,006,820
Permanent mortgages guaranteed by U.S. government agencies	40,594		17,465		13,803	115,679		11,846		199,387
Home equity	729,493		2,276		337	—		11,519		743,625
Total residential mortgage	1,749,473		23,040		15,420	115,679		46,220		1,949,832

Personal	838,811		589		263	5		290		839,958

Total	$	16,597,641	$	28,603	16,748	$	115,684	$	230,984	$	16,989,660

A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of June 30, 2016 is as follows (in thousands):



			Past Due
	Current		30 to 59 Days		60 to 89 Days	90 Days or More		Nonaccrual		Total
Commercial:
Energy	$	2,647,678	$	—	—	$	2,833	$	168,145	$	2,818,656
Services	2,817,217		494		3,765	—		9,388		2,830,864
Wholesale/retail	1,530,110		75		—	—		2,772		1,532,957
Manufacturing	595,110		—		—	—		293		595,403
Healthcare	2,050,271		—		—	—		875		2,051,146
Other commercial and industrial	526,691		76		82	46		516		527,411
Total commercial	10,167,077		645		3,847	2,879		181,989		10,356,437

Commercial real estate:
Residential construction and land development	153,315		—		—	—		4,261		157,576
Retail	794,154		—		—	—		1,265		795,419
Office	768,506		—		—	—		606		769,112
Multifamily	784,826		2,309		—	—		65		787,200
Industrial	645,510		—		—	—		76		645,586
Other commercial real estate	425,566		—		—	—		1,507		427,073
Total commercial real estate	3,571,877		2,309		—	—		7,780		3,581,966

Residential mortgage:
Permanent mortgage	935,857		5,798		124	—		27,228		969,007
Permanent mortgages guaranteed by U.S. government agencies	42,019		15,349		11,869	103,754		19,741		192,732
Home equity	707,024		1,889		159	20		10,092		719,184
Total residential mortgage	1,684,900		23,036		12,152	103,774		57,061		1,880,923

Personal	586,611		400		58	—		354		587,423

Total	$	16,010,465	$	26,390	16,057	$	106,653	$	247,184	$	16,406,749