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.

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.

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 original principal guarantee remains; 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.



	September 30, 2018								December 31, 2017
	Fixed Rate		Variable Rate		Non-accrual		Total		Fixed Rate		Variable Rate		Non-accrual		Total
Commercial	$	2,150,138	$	9,316,473	$	109,490	$	11,576,101	$	2,217,432	$	8,379,240	$	137,303	$	10,733,975
Commercial real estate	603,515		3,199,844		1,316		3,804,675		548,692		2,928,440		2,855		3,479,987
Residential mortgage	1,592,249		337,576		41,917		1,971,742		1,608,655		317,584		47,447		1,973,686
Personal	163,067		833,605		269		996,941		154,517		810,990		269		965,776
Total	$	4,508,969	$	13,687,498	$	152,992	$	18,349,459	$	4,529,296	$	12,436,254	$	187,874	$	17,153,424
Accruing loans past due (90 days)¹							$	518							$	633

At September 30, 2018, loans to businesses and collateral primarily located in Texas totaled $6.1 billion or 33 percent of the total loan portfolio. Loans to businesses and individuals with collateral primarily located in Oklahoma totaled $3.6 billion or 20 percent of our total loan portfolio. Loans for which the collateral location is not relevant, such as unsecured loans and reserve-based energy loans, are distributed by the borrower's primary operating location. These geographic concentrations subject the loan portfolio to the general economic conditions within these areas.

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.

The commercial loan portfolio segment is further divided into loan classes. The energy loan class totaled $3.3 billion or 18 percent of total loans at September 30, 2018, including $2.7 billion of outstanding loans to energy producers. Approximately 57 percent of committed production loans are secured by properties primarily producing oil and 43 percent are secured by properties producing natural gas. The services loan class totaled $3.0 billion or 16 percent of total loans at September 30, 2018. 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, educational services, consumer services, financial services and loans to entities providing services for real estate and construction. The healthcare loan class totaled $2.4 billion or 13 percent of total loans at September 30, 2018. 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 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.

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 3 years to ten years, then adjust annually thereafter.

At September 30, 2018, residential mortgage loans included $181 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 $696 million at September 30, 2018. Approximately 61 percent of the home equity loan portfolio is comprised of first lien loans and 39 percent of the home equity portfolio is comprised of junior lien loans. Junior lien loans are distributed 44 percent to amortizing term loans and 56 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 revolving period of 5 years followed by 15 years 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 revolving term of 5 years, subject to an update of certain credit information.

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 September 30, 2018, outstanding commitments totaled $10.7 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.

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 September 30, 2018, outstanding standby letters of credit totaled $672 million.

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 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 nine months ended September 30, 2018.

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.

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 September 30, 2018 is summarized as follows (in thousands):



	Commercial			Commercial Real Estate		Residential Mortgage			Personal			Nonspecific Allowance		Total
Allowance for loan losses:
Beginning balance	$	113,722		$	58,758	$	18,544		$	8,646		$	15,472	$	215,142
Provision for loan losses	(1,285		)	1,391		1			883			3,418		4,408
Loans charged off	(9,602		)	—		(91		)	(1,380		)	—		(11,073		)
Recoveries	1,263			40		229			560			—		2,092
Ending balance	$	104,098		$	60,189	$	18,683		$	8,709		$	18,890	$	210,569
Allowance for off-balance sheet credit losses:
Beginning balance	$	2,361		$	17	$	53		$	2		$	—	$	2,433
Provision for off-balance sheet credit losses	(424		)	19		(3		)	—			—		(408		)
Ending balance	$	1,937		$	36	$	50		$	2		$	—	$	2,025

Total provision for credit losses	$	(1,709	)	$	1,410	$	(2	)	$	883		$	3,418	$	4,000



	Commercial			Commercial Real Estate			Residential Mortgage			Personal			Nonspecific Allowance			Total
Allowance for loan losses:
Beginning balance	$	124,269		$	56,621		$	18,451		$	9,124		$	22,217		$	230,682
Provision for loan losses	2,720			248			(418		)	1,486			(3,327		)	709
Loans charged off	(24,940		)	—			(326		)	(3,802		)	—			(29,068		)
Recoveries	2,049			3,320			976			1,901			—			8,246
Ending balance	$	104,098		$	60,189		$	18,683		$	8,709		$	18,890		$	210,569
Allowance for off-balance sheet credit losses:
Beginning balance	$	3,644		$	45		$	43		$	2		$	—		$	3,734
Provision for off-balance sheet credit losses	(1,707		)	(9		)	7			—			—			(1,709		)
Ending balance	$	1,937		$	36		$	50		$	2		$	—		$	2,025

Total provision for credit losses	$	1,013		$	239		$	(411	)	$	1,486		$	(3,327	)	$	(1,000	)



	Commercial			Commercial Real Estate			Residential Mortgage			Personal			Nonspecific Allowance		Total
Allowance for loan losses:
Beginning balance	$	137,742		$	58,580		$	18,259		$	8,106		$	27,374	$	250,061
Provision for loan losses	2,474			(2,914		)	168			598			704		1,030
Loans charged off	(4,429		)	—			(168		)	(1,228		)	—		(5,825		)
Recoveries	1,014			739			134			550			—		2,437
Ending balance	$	136,801		$	56,405		$	18,393		$	8,026		$	28,078	$	247,703
Allowance for off-balance sheet credit losses:
Beginning balance	$	6,301		$	84		$	38		$	8		$	—	$	6,431
Provision for off-balance sheet credit losses	(976		)	(49		)	1			(6		)	—		(1,030		)
Ending balance	$	5,325		$	35		$	39		$	2		$	—	$	5,401

Total provision for credit losses	$	1,498		$	(2,963	)	$	169		$	592		$	704	$	—



	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	665			4,050			82			1,168			(122		)	5,843
Loans charged off	(6,556		)	(76		)	(444		)	(3,774		)	—			(10,850		)
Recoveries	2,479			1,682			531			1,859			—			6,551
Ending balance	$	136,801		$	56,405		$	18,393		$	8,026		$	28,078		$	247,703
Allowance for off-balance sheet credit losses:
Beginning balance	$	11,063		$	123		$	50		$	8		$	—		$	11,244
Provision for off-balance sheet credit losses	(5,738		)	(88		)	(11		)	(6		)	—			(5,843		)
Ending balance	$	5,325		$	35		$	39		$	2		$	—		$	5,401

Total provision for credit losses	$	(5,073	)	$	3,962		$	71		$	1,162		$	(122	)	$	—



	Collectively Measured for Impairment				Individually Measured for Impairment				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	11,466,611	$	90,301	$	109,490	$	13,797	$	11,576,101	$	104,098
Commercial real estate	3,803,359		60,189		1,316		—		3,804,675		60,189
Residential mortgage	1,929,825		18,683		41,917		—		1,971,742		18,683
Personal	996,672		8,709		269		—		996,941		8,709
Total	18,196,467		177,882		152,992		13,797		18,349,459		191,679

Nonspecific allowance	—		—		—		—		—		18,890

Total	$	18,196,467	$	177,882	$	152,992	$	13,797	$	18,349,459	$	210,569



	Collectively Measured for Impairment				Individually Measured for Impairment				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,596,672	$	115,438	$	137,303	$	8,831	$	10,733,975	$	124,269
Commercial real estate	3,477,132		56,621		2,855		—		3,479,987		56,621
Residential mortgage	1,926,239		18,451		47,447		—		1,973,686		18,451
Personal	965,507		9,124		269		—		965,776		9,124
Total	16,965,550		199,634		187,874		8,831		17,153,424		208,465

Nonspecific allowance	—		—		—		—		—		22,217

Total	$	16,965,550	$	199,634	$	187,874	$	8,831	$	17,153,424	$	230,682



	Collectively Measured for Impairment				Individually Measured for Impairment				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,619,034	$	123,517	$	176,900	$	13,284	$	10,795,934	$	136,801
Commercial real estate	3,515,167		56,405		2,975		—		3,518,142		56,405
Residential mortgage	1,900,244		18,393		45,506		—		1,945,750		18,393
Personal	946,753		8,026		255		—		947,008		8,026
Total	16,981,198		206,341		225,636		13,284		17,206,834		219,625

Nonspecific allowance	—		—		—		—		—		28,078

Total	$	16,981,198	$	206,341	$	225,636	$	13,284	$	17,206,834	$	247,703

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.



	Internally Risk Graded				Non-Graded				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	11,549,529	$	103,185	$	26,572	$	913	$	11,576,101	$	104,098
Commercial real estate	3,804,675		60,189		—		—		3,804,675		60,189
Residential mortgage	262,612		3,099		1,709,130		15,584		1,971,742		18,683
Personal	916,587		6,509		80,354		2,200		996,941		8,709
Total	16,533,403		172,982		1,816,056		18,697		18,349,459		191,679

Nonspecific allowance	—		—		—		—		—		18,890

Total	$	16,533,403	$	172,982	$	1,816,056	$	18,697	$	18,349,459	$	210,569



	Internally Risk Graded				Non-Graded				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,706,035	$	123,383	$	27,940	$	886	$	10,733,975	$	124,269
Commercial real estate	3,479,987		56,621		—		—		3,479,987		56,621
Residential mortgage	234,477		2,947		1,739,209		15,504		1,973,686		18,451
Personal	877,390		6,461		88,386		2,663		965,776		9,124
Total	15,297,889		189,412		1,855,535		19,053		17,153,424		208,465

Nonspecific allowance	—		—		—		—		—		22,217

Total	$	15,297,889	$	189,412	$	1,855,535	$	19,053	$	17,153,424	$	230,682



	Internally Risk Graded				Non-Graded				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	10,750,657	$	135,846	$	45,277	$	955	$	10,795,934	$	136,801
Commercial real estate	3,518,142		56,405		—		—		3,518,142		56,405
Residential mortgage	226,306		3,068		1,719,444		15,325		1,945,750		18,393
Personal	856,030		6,043		90,978		1,983		947,008		8,026
Total	15,351,135		201,362		1,855,699		18,263		17,206,834		219,625

Nonspecific allowance	—		—		—		—		—		28,078

Total	$	15,351,135	$	201,362	$	1,855,699	$	18,263	$	17,206,834	$	247,703

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.



	Internally Risk Graded								Non-Graded
	Performing
	Pass		Other Loans Especially Mentioned		Accruing Substandard		Nonaccrual		Performing		Nonaccrual		Total
Commercial:
Energy	$	3,127,227	$	7,233	$	106,374	$	54,033	$	—	$	—	$	3,294,867
Services	2,974,082		27,337		11,795		4,097		—		—		3,017,311
Wholesale/retail	1,636,405		1,508		3,567		9,249		—		—		1,650,729
Manufacturing	631,198		7,265		12,917		9,202		—		—		660,582
Healthcare	2,402,801		2,614		16,204		15,704		—		—		2,437,323
Other commercial and industrial	471,188		385		—		17,144		26,511		61		515,289
Total commercial	11,242,901		46,342		150,857		109,429		26,511		61		11,576,101

Commercial real estate:
Residential construction and land development	99,694		1,828		—		350		—		—		101,872
Retail	737,313		—		21,333		777		—		—		759,423
Office	817,854		6,975		—		—		—		—		824,829
Multifamily	1,120,145		—		21		—		—		—		1,120,166
Industrial	695,554		—		1,220		—		—		—		696,774
Other commercial real estate	300,887		535		—		189		—		—		301,611
Total commercial real estate	3,771,447		9,338		22,574		1,316		—		—		3,804,675

Residential mortgage:
Permanent mortgage	259,106		—		2,520		986		810,445		21,869		1,094,926
Permanent mortgages guaranteed by U.S. government agencies	—		—		—		—		172,928		7,790		180,718
Home equity	—		—		—		—		684,826		11,272		696,098
Total residential mortgage	259,106		—		2,520		986		1,668,199		40,931		1,971,742

Personal	916,430		47		34		76		80,161		193		996,941

Total	$	16,189,884	$	55,727	$	175,985	$	111,807	$	1,774,871	$	41,185	$	18,349,459



	Internally Risk Graded								Non-Graded
	Performing
	Pass		Other Loans Especially Mentioned		Accruing Substandard		Nonaccrual		Performing		Nonaccrual		Total
Commercial:
Energy	$	2,632,986	$	60,288	$	144,598	$	92,284	$	—	$	—	$	2,930,156
Services	2,943,869		13,927		26,533		2,620		—		—		2,986,949
Wholesale/retail	1,443,917		19,263		5,502		2,574		—		—		1,471,256
Manufacturing	472,869		6,653		11,290		5,962		—		—		496,774
Healthcare	2,253,497		3,186		43,305		14,765		—		—		2,314,753
Other commercial and industrial	478,951		7		8,161		19,028		27,870		70		534,087
Total commercial	10,226,089		103,324		239,389		137,233		27,870		70		10,733,975

Commercial real estate:
Residential construction and land development	113,190		1,828		395		1,832		—		—		117,245
Retail	686,915		4,243		98		276		—		—		691,532
Office	824,408		7,087		—		275		—		—		831,770
Multifamily	979,969		—		48		—		—		—		980,017
Industrial	573,014		—		—		—		—		—		573,014
Other commercial real estate	285,506		145		286		472		—		—		286,409
Total commercial real estate	3,463,002		13,303		827		2,855		—		—		3,479,987

Residential mortgage:
Permanent mortgage	232,492		—		822		1,163		784,928		24,030		1,043,435
Permanent mortgages guaranteed by U.S. government agencies	—		—		—		—		188,327		9,179		197,506
Home equity	—		—		—		—		719,670		13,075		732,745
Total residential mortgage	232,492		—		822		1,163		1,692,925		46,284		1,973,686

Personal	875,696		1,548		63		83		88,200		186		965,776

Total	$	14,797,279	$	118,175	$	241,101	$	141,334	$	1,808,995	$	46,540	$	17,153,424



	Internally Risk Graded								Non-Graded
	Performing
	Pass		Other Loans Especially Mentioned		Accruing Substandard		Nonaccrual		Performing		Nonaccrual		Total
Commercial:
Energy	$	2,436,465	$	114,065	$	206,768	$	110,683	$	—	$	—	$	2,867,981
Services	2,932,577		26,372		7,390		1,174		—		—		2,967,513
Wholesale/retail	1,637,698		9,021		9,486		1,893		—		—		1,658,098
Manufacturing	486,383		7,181		16,823		9,059		—		—		519,446
Healthcare	2,150,099		31,855		33,051		24,446		—		—		2,239,451
Other commercial and industrial	458,796		52		9,820		29,500		45,132		145		543,445
Total commercial	10,102,018		188,546		283,338		176,755		45,132		145		10,795,934

Commercial real estate:
Residential construction and land development	110,178		—		—		1,924		—		—		112,102
Retail	724,887		689		—		289		—		—		725,865
Office	788,539		8,275		—		275		—		—		797,089
Multifamily	998,125		—		884		—		—		—		999,009
Industrial	591,080		—		—		—		—		—		591,080
Other commercial real estate	292,509		—		1		487		—		—		292,997
Total commercial real estate	3,505,318		8,964		885		2,975		—		—		3,518,142

Residential mortgage:
Permanent mortgage	224,235		393		462		1,216		764,252		23,407		1,013,965
Permanent mortgages guaranteed by U.S. government agencies	—		—		—		—		178,479		8,891		187,370
Home equity	—		—		—		—		732,423		11,992		744,415
Total residential mortgage	224,235		393		462		1,216		1,675,154		44,290		1,945,750

Personal	855,857		49		38		86		90,809		169		947,008

Total	$	14,687,428	$	197,952	$	284,723	$	181,032	$	1,811,095	$	44,604	$	17,206,834

A summary of impaired loans follows (in thousands):



	As of										For the				For the
	September 30, 2018										Three Months Ended				Nine Months Ended
			Recorded Investment								September 30, 2018				September 30, 2018
	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	$	73,600	$	54,033	$	28,180	$	25,853	$	5,305	$	59,815	$	—	$	73,159	$	—
Services	6,959		4,097		4,021		76		76		4,237		—		3,358		—
Wholesale/retail	14,281		9,249		2,227		7,022		4,102		11,672		—		5,911		—
Manufacturing²	9,212		9,202		6,217		2,985		2,985		6,096		—		7,582		—
Healthcare	25,923		15,704		13,162		2,542		1,329		15,915		—		15,235		—
Other commercial and industrial	26,645		17,205		17,205		—		—		17,499		—		18,151		—
Total commercial	156,620		109,490		71,012		38,478		13,797		115,234		—		123,396		—

Commercial real estate:
Residential construction and land development	1,306		350		350		—		—		350		—		1,091		—
Retail	7,951		777		777		—		—		923		—		527		—
Office	—		—		—		—		—		137		—		137		—
Multifamily	—		—		—		—		—		—		—		—		—
Industrial	—		—		—		—		—		—		—		—		—
Other commercial real estate	354		189		189		—		—		246		—		330		—
Total commercial real estate	9,611		1,316		1,316		—		—		1,656		—		2,085		—

Residential mortgage:
Permanent mortgage	27,603		22,855		22,855		—		—		22,980		318		24,024		947
Permanent mortgage guaranteed by U.S. government agencies¹	185,788		180,718		180,718		—		—		174,653		1,557		178,643		4,979
Home equity	13,048		11,272		11,272		—		—		11,472		—		12,174		—
Total residential mortgage	226,439		214,845		214,845		—		—		209,105		1,875		214,841		5,926

Personal	320		269		269		—		—		305		—		269		—

Total	$	392,990	$	325,920	$	287,442	$	38,478	$	13,797	$	326,300	$	1,875	$	340,591	$	5,926



			Recorded Investment
	Unpaid Principal Balance		Total		With No Allowance		With Allowance		Related Allowance
Commercial:
Energy	$	111,011	$	92,284	$	40,968	$	51,316	$	8,814
Services	5,324		2,620		2,620		—		—
Wholesale/retail	9,099		2,574		2,574		—		—
Manufacturing	6,073		5,962		5,962		—		—
Healthcare	25,140		14,765		14,765		—		—
Other commercial and industrial	27,957		19,098		19,080		18		17
Total commercial	184,604		137,303		85,969		51,334		8,831

Commercial real estate:
Residential construction and land development	3,285		1,832		1,832		—		—
Retail	509		276		276		—		—
Office	287		275		275		—		—
Multifamily	—		—		—		—		—
Industrial	—		—		—		—		—
Other commercial real estate	670		472		472		—		—
Total commercial real estate	4,751		2,855		2,855		—		—

Residential mortgage:
Permanent mortgage	30,435		25,193		25,193		—		—
Permanent mortgage guaranteed by U.S. government agencies¹	203,814		197,506		197,506		—		—
Home equity	14,548		13,075		13,075		—		—
Total residential mortgage	248,797		235,774		235,774		—		—

Personal	307		269		269		—		—

Total	$	438,459	$	376,201	$	324,867	$	51,334	$	8,831



											For the				For the
	As of September 30, 2017										Three Months Ended				Nine Months Ended
			Recorded Investment								September 30, 2017				September 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	$	133,643	$	110,683	$	45,169	$	65,514	$	4,944	$	117,338	$	—	$	121,591	$	—
Services	3,838		1,174		1,174		—		—		4,464		—		4,674		—
Wholesale/retail	8,418		1,893		1,893		—		—		6,256		—		6,650		—
Manufacturing	9,674		9,059		9,059		—		—		9,357		—		6,995		—
Healthcare	24,591		24,446		474		23,972		8,323		24,476		—		12,635		—
Other commercial and industrial	38,222		29,645		29,626		19		17		25,138		—		25,382		—
Total commercial	218,386		176,900		87,395		89,505		13,284		187,029		—		177,927		—

Commercial real estate:
Residential construction and land development	3,532		1,924		1,924		—		—		1,988		—		2,679		—
Retail	513		289		289		—		—		295		—		308		—
Office	287		275		275		—		—		335		—		351		—
Multifamily	—		—		—		—		—		5		—		19		—
Industrial	—		—		—		—		—		—		—		38		—
Other commercial real estate	671		487		487		—		—		752		—		855		—
Total commercial real estate	5,003		2,975		2,975		—		—		3,375		—		4,250		—

Residential mortgage:
Permanent mortgage	29,861		24,623		24,623		—		—		24,019		315		23,739		912
Permanent mortgage guaranteed by U.S. government agencies¹	193,594		187,370		187,370		—		—		188,461		1,884		199,532		5,809
Home equity	13,332		11,992		11,992		—		—		11,880		—		11,755		—
Total residential mortgage	236,787		223,985		223,985		—		—		224,360		2,199		235,026		6,721

Personal	290		255		255		—		—		263		—		273		—

Total	$	460,466	$	404,115	$	314,610	$	89,505	$	13,284	$	415,027	$	2,199	$	417,476	$	6,721

TDRs generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. During the three and nine months ended September 30, 2018, $31 million and $76 million of loans were restructured and $4.5 million and $10.2 million of loans designated as TDRs were charged off. During the three and nine months ended September 30, 2017, $11 million and $53 million of loans were restructured and $4.4 million and $4.4 million of loans designated as TDRs were charged off.



			Past Due
	Current		30 to 59 Days		60 to 89 Days		90 Days or More		Nonaccrual		Total
Commercial:
Energy	$	3,240,684	$	150	$	—	$	—	$	54,033	$	3,294,867
Services	3,006,581		4,908		1,725		—		4,097		3,017,311
Wholesale/retail	1,641,447		33		—		—		9,249		1,650,729
Manufacturing	648,242		3,138		—		—		9,202		660,582
Healthcare	2,421,166		453		—		—		15,704		2,437,323
Other commercial and industrial	498,066		18		—		—		17,205		515,289
Total commercial	11,456,186		8,700		1,725		—		109,490		11,576,101

Commercial real estate:
Residential construction and land development	101,185		337		—		—		350		101,872
Retail	758,646		—		—		—		777		759,423
Office	824,829		—		—		—		—		824,829
Multifamily	1,120,166		—		—		—		—		1,120,166
Industrial	696,774		—		—		—		—		696,774
Other commercial real estate	300,450		530		45		397		189		301,611
Total commercial real estate	3,802,050		867		45		397		1,316		3,804,675

Residential mortgage:
Permanent mortgage	1,064,618		5,721		1,732		—		22,855		1,094,926
Permanent mortgages guaranteed by U.S. government agencies	39,523		23,370		13,753		96,282		7,790		180,718
Home equity	682,940		1,609		156		121		11,272		696,098
Total residential mortgage	1,787,081		30,700		15,641		96,403		41,917		1,971,742

Personal	995,714		900		58		—		269		996,941

Total	$	18,041,031	$	41,167	$	17,469	$	96,800	$	152,992	$	18,349,459



			Past Due
	Current		30 to 59 Days		60 to 89 Days		90 Days or More		Nonaccrual		Total
Commercial:
Energy	$	2,833,668	$	—	$	4,204	$	—	$	92,284	$	2,930,156
Services	2,983,222		514		486		107		2,620		2,986,949
Wholesale/retail	1,468,284		398		—		—		2,574		1,471,256
Manufacturing	490,739		—		73		—		5,962		496,774
Healthcare	2,284,770		15,218		—		—		14,765		2,314,753
Other commercial and industrial	514,701		85		78		125		19,098		534,087
Total commercial	10,575,384		16,215		4,841		232		137,303		10,733,975

Commercial real estate:
Residential construction and land development	115,213		200		—		—		1,832		117,245
Retail	691,256		—		—		—		276		691,532
Office	831,118		254		—		123		275		831,770
Multifamily	979,625		22		370		—		—		980,017
Industrial	573,014		—		—		—		—		573,014
Other commercial real estate	285,937		—		—		—		472		286,409
Total commercial real estate	3,476,163		476		370		123		2,855		3,479,987

Residential mortgage:
Permanent mortgage	1,014,588		3,435		219		—		25,193		1,043,435
Permanent mortgages guaranteed by U.S. government agencies	22,692		18,978		13,468		133,189		9,179		197,506
Home equity	717,007		2,206		440		17		13,075		732,745
Total residential mortgage	1,754,287		24,619		14,127		133,206		47,447		1,973,686

Personal	964,374		681		191		261		269		965,776

Total	$	16,770,208	$	41,991	$	19,529	$	133,822	$	187,874	$	17,153,424



			Past Due
	Current		30 to 59 Days		60 to 89 Days		90 Days or More		Nonaccrual		Total
Commercial:
Energy	$	2,752,259	$	—	$	5,039	$	—	$	110,683	$	2,867,981
Services	2,963,746		2,343		250		—		1,174		2,967,513
Wholesale/retail	1,654,018		1,748		409		30		1,893		1,658,098
Manufacturing	508,231		—		2,156		—		9,059		519,446
Healthcare	2,214,849		156		—		—		24,446		2,239,451
Other commercial and industrial	513,748		52		—		—		29,645		543,445
Total commercial	10,606,851		4,299		7,854		30		176,900		10,795,934

Commercial real estate:
Residential construction and land development	109,994		184		—		—		1,924		112,102
Retail	724,850		726		—		—		289		725,865
Office	796,687		127		—		—		275		797,089
Multifamily	999,009		—		—		—		—		999,009
Industrial	591,080		—		—		—		—		591,080
Other commercial real estate	292,322		1		—		187		487		292,997
Total commercial real estate	3,513,942		1,038		—		187		2,975		3,518,142

Residential mortgage:
Permanent mortgage	985,183		3,705		454		—		24,623		1,013,965
Permanent mortgages guaranteed by U.S. government agencies	25,169		17,346		13,343		122,621		8,891		187,370
Home equity	728,884		3,066		445		28		11,992		744,415
Total residential mortgage	1,739,236		24,117		14,242		122,649		45,506		1,945,750

Personal	943,368		3,296		81		8		255		947,008

Total	$	16,803,397	$	32,750	$	22,177	$	122,874	$	225,636	$	17,206,834