Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	$ 29,990,897	$ 29,990,897	$ 29,216,218
Financing Receivable, Nonaccrual	128,476	128,476	148,997
Nonaccrual Loans, Current Portion	$ 64,000	$ 64,000	$ 80,000
Percent of current nonaccrual loans	50.00%	50.00%	53.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	16,000	16,000	23,000
Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,258,899	10,258,899	9,731,555
Financing Receivable, Nonaccrual	14,369	14,369	62,022
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,120,849	1,120,849	1,061,700
Financing Receivable, Nonaccrual	9,285	9,285	1,394
Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	11,379,748	11,379,748	10,793,255
Financing Receivable, Nonaccrual	23,654	23,654	63,416
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,070,635	5,070,635	5,124,245
Financing Receivable, Nonaccrual	18,913	18,913	0
Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,114,300	2,114,300	2,271,398
Financing Receivable, Nonaccrual	15	15	6
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,184,934	7,184,934	7,395,644
Financing Receivable, Nonaccrual	18,928	18,928	6
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	18,564,683	18,564,683	18,188,898
Financing Receivable, Nonaccrual	42,582	42,582	63,422
Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,803,083	7,803,083	7,864,891
Financing Receivable, Nonaccrual	70,138	70,138	71,142
Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,708,946	2,708,946	2,256,162
Financing Receivable, Nonaccrual	7,456	7,456	5,797
Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	651,379	651,379	628,526
Financing Receivable, Nonaccrual	8,231	8,231	8,508
Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	262,806	262,806	277,740
Financing Receivable, Nonaccrual	70	70	128
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	11,426,214	11,426,214	11,027,319
Financing Receivable, Nonaccrual	85,894	85,894	85,574
Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	29,806,662	29,806,662	28,983,708
Financial Asset, Not Past Due [Member] | Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,242,844	10,242,844	9,663,587
Financial Asset, Not Past Due [Member] | Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,109,355	1,109,355	1,059,948
Financial Asset, Not Past Due [Member] | Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	11,352,200	11,352,200	10,723,536
Financial Asset, Not Past Due [Member] | Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,036,091	5,036,091	5,086,117
Financial Asset, Not Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,114,197	2,114,197	2,271,392
Financial Asset, Not Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,150,288	7,150,288	7,357,509
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	18,502,488	18,502,488	18,081,044
Financial Asset, Not Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,719,316	7,719,316	7,780,304
Financial Asset, Not Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,686,032	2,686,032	2,232,906
Financial Asset, Not Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	640,002	640,002	615,810
Financial Asset, Not Past Due [Member] | Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	258,824	258,824	273,644
Financial Asset, Not Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	11,304,174	11,304,174	10,902,664
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	45,086	45,086	38,113
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	950	950	5,374
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,209	2,209	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,159	3,159	5,374
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,746	10,746	0
Financial Asset, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	72	72	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,818	10,818	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	13,977	13,977	5,374
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	13,477	13,477	13,294
Financial Asset, 30 to 59 Days Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	13,860	13,860	14,712
Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,507	2,507	3,500
Financial Asset, 30 to 59 Days Past Due [Member] | Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,265	1,265	1,233
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	31,109	31,109	32,739
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,566	3,566	23,712
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	262	262	191
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	358
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	262	262	549
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	18,697
Financial Asset, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	16	16	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	16	16	18,697
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	278	278	19,246
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	153	153	152
Financial Asset, 60 to 89 Days Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,598	1,598	2,674
Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	639	639	708
Financial Asset, 60 to 89 Days Past Due [Member] | Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	898	898	932
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,288	3,288	4,467
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,107	7,107	21,689
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	474	474	380
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	474	474	380
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	4,885	4,885	19,432
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	4,885	4,885	19,432
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,359	5,359	19,812
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	73
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	0	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,748	1,748	1,803
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	$ 1,748	$ 1,748	$ 1,876