Loans and Allowances for Credit Losses, Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 235,704	$ 256,421
Provision for loan losses	14,525	(3,967)
Loans charged off	(3,667)	(7,805)
Recoveries of loans previously charged off	2,898	1,824
Ending balance	249,460	246,473
Provision Details [Abstract]
Provision for credit losses	16,000	0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	60,919	32,977
Provision for off-balance sheet credit risk	2,024	3,268
Ending balance	62,943	36,245
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	22,629,758		$ 22,435,353
Individually measured for impairment, recorded investment	120,295		121,797
Total	22,750,053		22,557,150
Related allowance [Abstract]
Collectively measured for impairment, related allowance	245,427		230,134
Individually measured for impairment, related allowance	4,033		5,570
Total	249,460		235,704
Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	131,586	162,056
Provision for loan losses	6,330	(5,118)
Loans charged off	(12)	(6,081)
Recoveries of loans previously charged off	1,994	591
Ending balance	139,898	151,448
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	18,246	13,812
Provision for off-balance sheet credit risk	2,362	154
Ending balance	20,608	13,966
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	14,162,917		14,152,202
Individually measured for impairment, recorded investment	54,432		60,297
Total	14,217,349		14,212,499
Related allowance [Abstract]
Collectively measured for impairment, related allowance	137,415		127,566
Individually measured for impairment, related allowance	2,483		4,020
Total	139,898		131,586
Commercial real estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	57,648	58,553
Provision for loan losses	10,426	468
Loans charged off	(2,208)	(191)
Recoveries of loans previously charged off	137	144
Ending balance	66,003	58,974
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	40,490	17,442
Provision for off-balance sheet credit risk	(279)	3,023
Ending balance	40,211	20,465
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	4,793,648		4,590,207
Individually measured for impairment, recorded investment	21,668		16,570
Total	4,815,316		4,606,777
Related allowance [Abstract]
Collectively measured for impairment, related allowance	64,453		56,098
Individually measured for impairment, related allowance	1,550		1,550
Total	66,003		57,648
Loans to individuals [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	46,470	35,812
Provision for loan losses	(2,231)	683
Loans charged off	(1,447)	(1,533)
Recoveries of loans previously charged off	767	1,089
Ending balance	43,559	36,051
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance	2,183	1,723
Provision for off-balance sheet credit risk	(59)	91
Ending balance	2,124	$ 1,814
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	3,673,193		3,692,944
Individually measured for impairment, recorded investment	44,195		44,930
Total	3,717,388		3,737,874
Related allowance [Abstract]
Collectively measured for impairment, related allowance	43,559		46,470
Individually measured for impairment, related allowance	0		0
Total	$ 43,559		$ 46,470

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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The balance of financing receivables that were collectively evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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