Loans and Allowances for Credit Losses (Tables)

6 Months Ended

Jun. 30, 2022

Loans and Leases Receivable, Net Amount [Abstract]

Schedule of Loans by Portfolio Segment [Table Text Block]

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

	June 30, 2022								December 31, 2021
	Fixed Rate		Variable Rate		Non-accrual		Total		Fixed Rate		Variable Rate		Non-accrual		Total
Commercial	$	3,410,376	$	10,113,713	$	54,608	$	13,578,697	$	3,360,117	$	9,072,244	$	74,104	$	12,506,465
Commercial real estate	874,850		3,220,359		10,939		4,106,148		929,015		2,888,048		14,262		3,831,325
Paycheck protection program	43,140		—		—		43,140		276,341		—		—		276,341
Loans to individuals	2,011,043		1,503,528		48,592		3,563,163		2,037,792		1,508,064		45,693		3,591,549
Total	$	6,339,409	$	14,837,600	$	114,139	$	21,291,148	$	6,603,265	$	13,468,356	$	134,059	$	20,205,680

Rollforward of Allowance For Loan Losses And Accrual for Off-Balance Sheet Credit Losses [Table Text Block]

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 is summarized as follows (in thousands):

	Three Months Ended
	June 30, 2022
	Commercial		Commercial Real Estate		Paycheck Protection Program		Loans to Individuals		Total
Allowance for loan losses:
Beginning balance	$	151,448	$	58,974	$	—	$	36,051	$	246,473
Provision for loan losses	(15,468)		4,085		—		5,225		(6,158)
Loans charged off	(6)		(78)		—		(1,284)		(1,368)
Recoveries of loans previously charged off	1,588		16		—		563		2,167
Ending Balance	$	137,562	$	62,997	$	—	$	40,555	$	241,114
Allowance for off-balance sheet credit risk from unfunded loan commitments:
Beginning balance	$	13,966	$	20,465	$	—	$	1,814	$	36,245
Provision for off-balance sheet credit risk	1,873		4,205		—		(73)		6,005
Ending Balance	$	15,839	$	24,670	$	—	$	1,741	$	42,250

	Six Months Ended
	June 30, 2022
	Commercial		Commercial Real Estate		Paycheck Protection Program		Loans to Individuals		Total
Allowance for loan losses:
Beginning balance	$	162,056	$	58,553	$	—	$	35,812	$	256,421
Provision for loan losses	(20,586)		4,553		—		5,908		(10,125)
Loans charged off	(6,087)		(269)		—		(2,817)		(9,173)
Recoveries	2,179		160		—		1,652		3,991
Ending balance	$	137,562	$	62,997	$	—	$	40,555	$	241,114
Allowance for off-balance sheet credit risk from unfunded loan commitments:
Beginning balance	$	13,812	$	17,442	$	—	$	1,723	$	32,977
Provision for off-balance sheet credit losses	2,027		7,228		—		18		9,273
Ending balance	$	15,839	$	24,670	$	—	$	1,741	$	42,250

	Three Months Ended
	June 30, 2021
	Commercial		Commercial Real Estate		Paycheck Protection Program		Loans to Individuals		Total
Allowance for loan losses:
Beginning balance	$	231,372	$	81,746	$	—	$	39,284	$	352,402
Provision for loan losses	(18,442)		(10,582)		—		3,960		(25,064)
Loans charged off	(16,502)		(800)		—		(1,002)		(18,304)
Recoveries of loans previously charged off	1,875		176		—		805		2,856
Ending Balance	$	198,303	$	70,540	$	—	$	43,047	$	311,890
Allowance for off-balance sheet credit risk from unfunded loan commitments:
Beginning balance	$	12,736	$	18,298	$	—	$	1,843	$	32,877
Provision for off-balance sheet credit risk	(2,642)		(5,950)		—		2		(8,590)
Ending Balance	$	10,094	$	12,348	$	—	$	1,845	$	24,287

	Six Months Ended
	June 30, 2021
	Commercial		Commercial Real Estate		Paycheck Protection Program		Loans to Individuals		Total
Allowance for loan losses:
Beginning balance	$	254,934	$	86,558	$	—	$	47,148	$	388,640
Provision for loan losses	(28,335)		(15,161)		—		(3,338)		(46,834)
Loans charged off	(31,847)		(1,063)		—		(2,299)		(35,209)
Recoveries of loans previously charged off	3,551		206		—		1,536		5,293
Ending Balance	$	198,303	$	70,540	$	—	$	43,047	$	311,890
Allowance for off-balance sheet credit risk from unfunded loan commitments:
Beginning balance	$	14,422	$	20,571	$	—	$	1,928	$	36,921
Provision for off-balance sheet credit risk	(4,328)		(8,223)		—		(83)		(12,634)
Ending Balance	$	10,094	$	12,348	$	—	$	1,845	$	24,287

Changes in our reasonable and supportable forecasts of macroeconomic variables resulted in a $305 thousand provision for credit losses related to lending activities during the second quarter of 2022. An increase in required provision due to loan growth and changes in our economic outlook was offset by a sustained trend of improving credit quality metrics. Changes in the loan portfolio characteristics, including specific impairment and losses, loan balances, risk grading and changes in payment profile resulted in a $458 thousand negative provision for credit losses related to lending activities.

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at June 30, 2022 is as follows (in thousands):

	Collectively Measured for General Allowances				Individually Measured for Specific Allowances				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	13,524,089	$	135,209	$	54,608	$	2,353	$	13,578,697	$	137,562
Commercial real estate	4,095,209		62,062		10,939		935		4,106,148		62,997
Paycheck protection program	43,140		—		—		—		43,140		—
Loans to individuals	3,514,571		40,555		48,592		—		3,563,163		40,555
Total	$	21,177,009	$	237,826	$	114,139	$	3,288	$	21,291,148	$	241,114

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at December 31, 2021 is as follows (in thousands):

	Collectively Measured for General Allowances				Individually Measured for Specific Allowances				Total
	Recorded Investment		Related Allowance		Recorded Investment		Related Allowance		Recorded Investment		Related Allowance
Commercial	$	12,432,361	$	158,063	$	74,104	$	3,993	$	12,506,465	$	162,056
Commercial real estate	3,817,063		56,204		14,262		2,349		3,831,325		58,553
Paycheck protection program	276,341		—		—		—		276,341		—
Loans to individuals	3,545,856		35,812		45,693		—		3,591,549		35,812
Total	$	20,071,621	$	250,079	$	134,059	$	6,342	$	20,205,680	$	256,421

Schedule of Credit Quality Indicators [Table Text Block]

The following table summarizes the Company’s loan portfolio at June 30, 2022 by the risk grade categories and vintage (in thousands): 

	Origination Year
	2022		2021		2020		2019		2018		Prior		Revolving Loans		Revolving Loans Converted to Term Loans		Total
Commercial:
Energy
Pass	$	109,094	$	126,603	$	34,298	$	14,287	$	7,490	$	8,606	$	3,027,640	$	6,661	$	3,334,679
Accruing Substandard	—		—		—		1,093		501		695		25,655		9,525		37,469
Nonaccrual	—		—		16,310		—		—		472		4,142		—		20,924
Total energy	109,094		126,603		50,608		15,380		7,991		9,773		3,057,437		16,186		3,393,072
Healthcare
Pass	516,924		607,642		533,637		504,011		462,368		839,735		174,439		24		3,638,780
Special Mention	—		—		—		9,515		—		—		5		—		9,520
Accruing Substandard	—		—		—		26,816		—		6,962		—		—		33,778
Nonaccrual	—		—		—		—		6,533		8,352		—		—		14,885
Total healthcare	516,924		607,642		533,637		540,342		468,901		855,049		174,444		24		3,696,963
Services
Pass	307,329		604,668		324,439		245,344		187,252		892,138		778,201		746		3,340,117
Special Mention	330		432		410		822		985		86		21,900		168		25,133
Accruing Substandard	—		—		384		3,837		57		2,909		33,797		—		40,984
Nonaccrual	—		—		234		—		—		14,899		126		—		15,259
Total services	307,659		605,100		325,467		250,003		188,294		910,032		834,024		914		3,421,493
General business
Pass	416,644		480,471		199,287		219,367		162,518		309,630		1,234,314		1,885		3,024,116
Special Mention	—		937		—		9,355		29		6,137		8,446		—		24,904
Accruing Substandard	—		—		115		605		4,743		9,028		119		—		14,610
Nonaccrual	—		—		1,093		736		979		16		709		6		3,539
Total general business	416,644		481,408		200,495		230,063		168,269		324,811		1,243,588		1,891		3,067,169
Total commercial	1,350,321		1,820,753		1,110,207		1,035,788		833,455		2,099,665		5,309,493		19,015		13,578,697
Commercial real estate:
Pass	450,221		1,084,348		633,124		747,272		310,651		736,285		112,717		—		4,074,618
Special Mention	—		—		—		—		—		17,478		—		—		17,478
Accruing Substandard	—		—		—		—		—		3,113		—		—		3,113
Nonaccrual	—		—		—		7,739		—		3,200		—		—		10,939
Total commercial real estate	450,221		1,084,348		633,124		755,011		310,651		760,076		112,717		—		4,106,148

	Origination Year
	2022		2021		2020		2019		2018		Prior		Revolving Loans		Revolving Loans Converted to Term Loans		Total
Paycheck protection program:
Pass	—		30,389		12,751		—		—		—		—		—		43,140
Total paycheck protection program	—		30,389		12,751		—		—		—		—		—		43,140
Loans to individuals:
Residential mortgage
Pass	181,189		386,210		410,339		70,161		43,769		297,196		341,992		22,409		1,753,265
Special Mention	—		60		—		17		166		329		238		—		810
Accruing Substandard	—		—		—		34		—		131		29		—		194
Nonaccrual	34		1,509		2,519		356		1,995		21,180		2,059		808		30,460
Total residential mortgage	181,223		387,779		412,858		70,568		45,930		318,836		344,318		23,217		1,784,729
Residential mortgage guaranteed by U.S. government agencies
Pass	—		2,218		10,722		14,035		21,325		227,538		—		—		275,838
Nonaccrual	—		—		431		2,087		2,295		13,187		—		—		18,000
Total residential mortgage guaranteed by U.S. government agencies	—		2,218		11,153		16,122		23,620		240,725		—		—		293,838
Personal:
Pass	90,206		215,139		170,635		172,046		70,564		211,023		553,611		486		1,483,710
Special Mention	5		34		43		6		16		46		—		—		150
Accruing Substandard	8		433		—		160		—		—		3		—		604
Nonaccrual	—		31		17		26		11		23		24		—		132
Total personal	90,219		215,637		170,695		172,238		70,591		211,092		553,638		486		1,484,596
Total loans to individuals	271,442		605,634		594,706		258,928		140,141		770,653		897,956		23,703		3,563,163
Total loans	$	2,071,984	$	3,541,124	$	2,350,788	$	2,049,727	$	1,284,247	$	3,630,394	$	6,320,166	$	42,718	$	21,291,148

The following table summarizes the Company’s loan portfolio at December 31, 2021 by the risk grade categories and vintage (in thousands): 

	Origination Year
	2021		2020		2019		2018		2017		Prior		Revolving Loans		Revolving Loans Converted to Term Loans		Total
Commercial:
Energy
Pass	$	252,133	$	29,556	$	15,914	$	13,548	$	4,741	$	6,765	$	2,540,525	$	—	$	2,863,182
Special Mention	558		771		—		—		—		—		750		—		2,079
Accruing Substandard	10,650		22,611		1,185		814		—		716		74,556		—		110,532
Nonaccrual	—		20,487		—		—		—		714		9,890		—		31,091
Total energy	263,341		73,425		17,099		14,362		4,741		8,195		2,625,721		—		3,006,884
Healthcare
Pass	563,800		589,193		516,558		498,998		319,096		688,136		160,154		26		3,335,961
Special Mention	6,835		—		15,583		—		11,135		—		5		—		33,558
Accruing Substandard	—		—		27,135		543		—		1,981		—		—		29,659
Nonaccrual	—		—		—		6,542		—		8,711		509		—		15,762
Total healthcare	570,635		589,193		559,276		506,083		330,231		698,828		160,668		26		3,414,940
Services
Pass	696,149		405,057		289,375		275,010		225,404		795,029		607,958		375		3,294,357
Special Mention	434		405		1,830		1,047		3,290		47		17,210		192		24,455
Accruing Substandard	43		530		4,166		10,714		1,785		2,366		11,607		—		31,211
Nonaccrual	—		—		—		230		13,918		2,519		503		—		17,170
Total services	696,626		405,992		295,371		287,001		244,397		799,961		637,278		567		3,367,193
General business
Pass	584,438		211,892		264,462		177,384		168,977		215,014		1,047,420		2,284		2,671,871
Special Mention	218		223		60		1,435		3,842		—		5,875		—		11,653
Accruing Substandard	265		1,066		1,634		7,697		8,336		3,024		1,821		—		23,843
Nonaccrual	—		2,444		4,562		1,046		762		518		730		19		10,081
Total general business	584,921		215,625		270,718		187,562		181,917		218,556		1,055,846		2,303		2,717,448
Total commercial	2,115,523		1,284,235		1,142,464		995,008		761,286		1,725,540		4,479,513		2,896		12,506,465
Commercial real estate:
Pass	717,400		711,231		871,283		403,115		279,058		664,684		117,847		31		3,764,649
Special Mention	—		—		—		6,660		10,898		9,244		—		—		26,802
Accruing Substandard	—		—		—		13,352		4,480		7,780		—		—		25,612
Nonaccrual	—		—		8,076		—		—		6,186		—		—		14,262
Total commercial real estate	717,400		711,231		879,359		423,127		294,436		687,894		117,847		31		3,831,325

	Origination Year
	2021		2020		2019		2018		2017		Prior		Revolving Loans		Revolving Loans Converted to Term Loans		Total
Paycheck protection program:
Pass	237,357		38,984		—		—		—		—		—		—		276,341
Total paycheck protection program	237,357		38,984		—		—		—		—		—		—		276,341
Loans to individuals:
Residential mortgage
Pass	386,092		452,537		84,001		60,390		68,150		295,632		320,638		21,463		1,688,903
Special Mention	—		—		156		—		19		411		282		159		1,027
Accruing Substandard	98		—		—		—		127		41		400		—		666
Nonaccrual	1,516		1,809		383		1,968		629		22,289		2,177		803		31,574
Total residential mortgage	387,706		454,346		84,540		62,358		68,925		318,373		323,497		22,425		1,722,170
Residential mortgage guaranteed by U.S. government agencies
Pass	699		11,380		20,650		27,970		32,742		246,871		—		—		340,312
Nonaccrual	—		—		1,259		821		635		11,146		—		—		13,861
Total residential mortgage guaranteed by U.S. government agencies	699		11,380		21,909		28,791		33,377		258,017		—		—		354,173
Personal:
Pass	218,960		180,577		177,389		70,249		92,592		135,041		638,713		728		1,514,249
Special Mention	—		9		34		3		—		47		—		—		93
Accruing Substandard	435		5		165		—		—		1		—		—		606
Nonaccrual	110		14		10		24		35		40		25		—		258
Total personal	219,505		180,605		177,598		70,276		92,627		135,129		638,738		728		1,515,206
Total loans to individuals	607,910		646,331		284,047		161,425		194,929		711,519		962,235		23,153		3,591,549
Total loans	$	3,678,190	$	2,680,781	$	2,305,870	$	1,579,560	$	1,250,651	$	3,124,953	$	5,559,595	$	26,080	$	20,205,680

Financing Receivable, Nonaccrual [Table Text Block]

A summary of nonaccruing loans at June 30, 2022 follows (in thousands): 

	As of June 30, 2022
	Total		With No Allowance		With Allowance		Related Allowance
Commercial:
Energy	$	20,924	$	20,924	$	—	$	—
Healthcare	14,886		8,353		6,533		946
Services	15,259		11,798		3,461		1,407
General business	3,539		3,539		—		—
Total commercial	54,608		44,614		9,994		2,353
Commercial real estate	10,939		3,200		7,739		935
Loans to individuals:
Residential mortgage	30,460		30,460		—		—
Residential mortgage guaranteed by U.S. government agencies	18,000		18,000		—		—
Personal	132		132		—		—
Total loans to individuals	48,592		48,592		—		—
Total	$	114,139	$	96,406	$	17,733	$	3,288

A summary of nonaccruing loans at December 31, 2021 follows (in thousands): 

	As of December 31, 2021
	Total		With No Allowance		With Allowance		Related Allowance
Commercial:
Energy	$	31,091	$	31,091	$	—	$	—
Healthcare	15,762		9,679		6,083		53
Services	17,170		13,686		3,484		2,584
General business	10,081		7,690		2,391		1,357
Total commercial	74,104		62,146		11,958		3,994
Commercial real estate	14,262		6,186		8,076		2,349
Loans to individuals:
Residential mortgage	31,574		31,574		—		—
Residential mortgage guaranteed by U.S. government agencies	13,861		13,861		—		—
Personal	258		258		—		—
Total loans to individuals	45,693		45,693		—		—
Total	$	134,059	$	114,025	$	20,034	$	6,343

Summary of Loans by Aging Status [Table Text Block]

A summary of loans currently performing and past due as of June 30, 2022 is as follows (in thousands):

			Past Due								Past Due 90 Days or More and Accruing
	Current		30 to 59 Days		60 to 89 Days		90 Days or More		Total
Commercial:
Energy	$	3,393,072	$	—	$	—	$	—	$	3,393,072	$	—
Healthcare	3,688,256		2,178		—		6,529		3,696,963		—
Services	3,413,226		198		—		8,069		3,421,493		—
General business	3,065,236		489		1,444		—		3,067,169		—
Total commercial	13,559,790		2,865		1,444		14,598		13,578,697		—
Commercial real estate	4,102,920		28		—		3,200		4,106,148		—
Paycheck protection program	42,651		27		459		3		43,140		3
Loans to individuals:
Residential mortgage	1,766,354		10,904		1,828		5,643		1,784,729		—
Residential mortgage guaranteed by U.S. government agencies	138,675		35,574		19,659		99,930		293,838		87,470
Personal	1,482,287		671		1,615		23		1,484,596		—
Total loans to individuals	3,387,316		47,149		23,102		105,596		3,563,163		87,470
Total	$	21,092,677	$	50,069	$	25,005	$	123,397	$	21,291,148	$	87,473

A summary of loans currently performing and past due as of December 31, 2021 is as follows (in thousands):

			Past Due								Past Due 90 Days or More and Accruing
	Current		30 to 59 Days		60 to 89 Days		90 Days or More		Total
Commercial:
Energy	$	3,002,623	$	545	$	3,716	$	—	$	3,006,884	$	—
Healthcare	3,412,072		2,359		—		509		3,414,940		—
Services	3,352,639		920		4,620		9,014		3,367,193		—
General business	2,705,596		6,080		997		4,775		2,717,448		199
Total commercial	12,472,930		9,904		9,333		14,298		12,506,465		199
Commercial real estate	3,827,962		—		206		3,157		3,831,325		—
Paycheck protection program	276,341		—		—		—		276,341		74
Loans to individuals:
Residential mortgage	1,707,654		6,263		1,556		6,697		1,722,170		—
Residential mortgage guaranteed by U.S. government agencies	181,022		26,869		16,751		129,531		354,173		118,819
Personal	1,514,938		66		24		178		1,515,206		40
Total loans to individuals	3,403,614		33,198		18,331		136,406		3,591,549		118,859
Total	$	19,980,847	$	43,102	$	27,870	$	153,861	$	20,205,680	$	119,132