Loans and Allowances for Credit Losses, Activity in Allowance for Credit Losses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for loan losses [Roll Forward]
Beginning balance - CECL	$ 388,640,000	$ 236,568,000
Provision for loan losses - CECL	(95,202,000)	222,460,000
Loans charged off	(51,351,000)	(79,399,000)	$ (50,977,000)
Recoveries of loans previously charged off	14,334,000	9,011,000	10,074,000
Ending Balance - CECL	256,421,000	388,640,000	236,568,000
Beginning balance, Incurred Loss Model	388,640,000	210,759,000	207,457,000
Provision for loan losses			44,205,000
Ending balance, Incurred Loss Model	256,421,000	388,640,000	210,759,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL	36,921,000	25,137,000
Provision for off-balance sheet credit risk	(3,944,000)	11,784,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL	32,977,000	36,921,000	25,137,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred loss model		1,585,000	1,790,000
Provision for off-balance sheet credit losses			(205,000)
Ending balance - Incurred loss model			1,585,000
Total provision for credit losses	(100,000,000)	222,592,000	44,000,000
Provision Details [Abstract]
Change in provision due to changes in reasonable and supportable forecasts, primarily due to COVID-19 pandemic [Line Items]	(90,100,000)
Other changes to provision	(9,000,000)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	20,071,621,000	22,772,827,000
Individually measured for impairment, recorded investment	134,059,000	234,693,000
Total	20,205,680,000	23,007,520,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	250,079,000	366,199,000
Individually measured for impairment, related allowance	6,342,000	22,441,000
Loans and Leases Receivable, Allowance, Total	256,421,000	388,640,000	210,759,000
Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL	254,934,000	151,868,000
Provision for loan losses - CECL	(59,326,000)	171,800,000
Loans charged off	(43,956,000)	(73,370,000)	(43,185,000)
Recoveries of loans previously charged off	10,404,000	4,636,000	2,021,000
Ending Balance - CECL	162,056,000	254,934,000	151,868,000
Beginning balance, Incurred Loss Model		118,187,000	102,226,000
Provision for loan losses			57,125,000
Ending balance, Incurred Loss Model			118,187,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL	14,422,000	11,578,000
Provision for off-balance sheet credit risk	(610,000)	2,844,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL	13,812,000	14,422,000	11,578,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred loss model		1,434,000	1,655,000
Provision for off-balance sheet credit losses			(221,000)
Ending balance - Incurred loss model			1,434,000
Total provision for credit losses			56,904,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	12,432,361,000	12,910,376,000
Individually measured for impairment, recorded investment	74,104,000	167,159,000
Total	12,506,465,000	13,077,535,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	158,063,000	235,882,000
Individually measured for impairment, related allowance	3,993,000	19,052,000
Loans and Leases Receivable, Allowance, Total			118,187,000
Commercial real estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL	86,558,000	47,185,000
Provision for loan losses - CECL	(26,522,000)	40,407,000
Loans charged off	(2,485,000)	(1,300,000)	(1,161,000)
Recoveries of loans previously charged off	1,002,000	266,000	4,986,000
Ending Balance - CECL	58,553,000	86,558,000	47,185,000
Beginning balance, Incurred Loss Model		51,805,000	60,026,000
Provision for loan losses			(12,046,000)
Ending balance, Incurred Loss Model			51,805,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL	20,571,000	11,767,000
Provision for off-balance sheet credit risk	(3,129,000)	8,804,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL	17,442,000	20,571,000	11,767,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred loss model		107,000	52,000
Provision for off-balance sheet credit losses			55,000
Ending balance - Incurred loss model			107,000
Total provision for credit losses			(11,991,000)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	3,817,063,000	4,671,292,000
Individually measured for impairment, recorded investment	14,262,000	27,246,000
Total	3,831,325,000	4,698,538,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	56,204,000	83,169,000
Individually measured for impairment, related allowance	2,349,000	3,389,000
Loans and Leases Receivable, Allowance, Total			51,805,000
Paycheck Protection Program
Allowance for loan losses [Roll Forward]
Beginning balance - CECL	0	0
Provision for loan losses - CECL	0	10,253,000
Loans charged off	0	(4,729,000)
Recoveries of loans previously charged off	0	4,109,000
Ending Balance - CECL	0	0	0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL	0	0
Provision for off-balance sheet credit risk	0	136,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL	0	0	0
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	276,341,000	1,682,310,000
Individually measured for impairment, recorded investment	0	0
Total	276,341,000	1,682,310,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	0	0
Individually measured for impairment, related allowance	0	0
Loans to individuals [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL	47,148,000	37,515,000
Provision for loan losses - CECL	(9,354,000)	0
Loans charged off	(4,910,000)	0
Recoveries of loans previously charged off	2,928,000	0
Ending Balance - CECL	35,812,000	47,148,000	37,515,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL	1,928,000	1,792,000
Provision for off-balance sheet credit risk	(205,000)	0
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL	1,723,000	1,928,000	1,792,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	3,545,856,000	3,508,849,000
Individually measured for impairment, recorded investment	45,693,000	40,288,000
Total	3,591,549,000	3,549,137,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	35,812,000	47,148,000
Individually measured for impairment, related allowance	0	0
Loans to individuals [Member] | Residential Mortgage [Member]
Allowance for loan losses [Roll Forward]
Loans charged off			(288,000)
Recoveries of loans previously charged off			562,000
Beginning balance, Incurred Loss Model		14,400,000	17,964,000
Provision for loan losses			(3,838,000)
Ending balance, Incurred Loss Model			14,400,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred loss model		44,000	52,000
Provision for off-balance sheet credit losses			(8,000)
Ending balance - Incurred loss model			44,000
Total provision for credit losses			(3,846,000)
Related allowance [Abstract]
Loans and Leases Receivable, Allowance, Total			14,400,000
Loans to individuals [Member] | Personal [Member]
Allowance for loan losses [Roll Forward]
Loans charged off			(6,343,000)
Recoveries of loans previously charged off			2,505,000
Beginning balance, Incurred Loss Model		9,172,000	9,473,000
Provision for loan losses			3,537,000
Ending balance, Incurred Loss Model			9,172,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred loss model		0	31,000
Provision for off-balance sheet credit losses			(31,000)
Ending balance - Incurred loss model			0
Total provision for credit losses			3,506,000
Related allowance [Abstract]
Loans and Leases Receivable, Allowance, Total			9,172,000
Nonspecific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL	0	0
Provision for loan losses - CECL	0	0
Loans charged off	0	0	0
Recoveries of loans previously charged off	0	0	0
Ending Balance - CECL	0	0	0
Beginning balance, Incurred Loss Model		17,195,000	17,768,000
Provision for loan losses			(573,000)
Ending balance, Incurred Loss Model			17,195,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL	0	0
Provision for off-balance sheet credit risk	0	0
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL	$ 0	0	0
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred loss model		0	0
Provision for off-balance sheet credit losses			0
Ending balance - Incurred loss model			0
Total provision for credit losses			(573,000)
Related allowance [Abstract]
Loans and Leases Receivable, Allowance, Total			17,195,000
Transition Adjustment [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		25,809,000
Ending Balance - CECL			25,809,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		23,552,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			23,552,000
Transition Adjustment [Member] | Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		33,681,000
Ending Balance - CECL			33,681,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		10,144,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			10,144,000
Transition Adjustment [Member] | Commercial real estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		(4,620,000)
Ending Balance - CECL			(4,620,000)
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		11,660,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			11,660,000
Transition Adjustment [Member] | Paycheck Protection Program
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		13,943,000
Ending Balance - CECL			13,943,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		1,748,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			1,748,000
Transition Adjustment [Member] | Loans to individuals [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		0
Ending Balance - CECL			0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		0
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			0
Transition Adjustment [Member] | Nonspecific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		(17,195,000)
Ending Balance - CECL			(17,195,000)
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		0
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			0
Previously Reported [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		210,759,000
Ending Balance - CECL			210,759,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		1,585,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			1,585,000
Previously Reported [Member] | Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		118,187,000
Ending Balance - CECL			118,187,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		1,434,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			1,434,000
Previously Reported [Member] | Commercial real estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		51,805,000
Ending Balance - CECL			51,805,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		107,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			107,000
Previously Reported [Member] | Paycheck Protection Program
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		23,572,000
Ending Balance - CECL			23,572,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		44,000
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			44,000
Previously Reported [Member] | Loans to individuals [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		0
Ending Balance - CECL			0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		0
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			0
Previously Reported [Member] | Nonspecific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance - CECL		17,195,000
Ending Balance - CECL			17,195,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance - CECL		$ 0
Off-Balance Sheet, Credit Loss, Liability, Ending Balance - CECL			$ 0