Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	$ 30,951,964	$ 30,951,964	$ 29,768,586
Financing Receivable, Nonaccrual	106,179	106,179	123,260
Nonaccrual Loans, Current Portion	$ 38,000	$ 38,000	$ 52,400
Percent of current nonaccrual loans	36.00%	36.00%	42.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	14,800	14,800	23,800
Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	11,567,651	11,567,651	10,573,741
Financing Receivable, Nonaccrual	12,802	12,802	19,084
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,149,939	1,149,939	1,143,741
Financing Receivable, Nonaccrual	203	203	1,501
Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	12,717,590	12,717,590	11,717,483
Financing Receivable, Nonaccrual	13,006	13,006	20,585
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,369,441	5,369,441	5,227,975
Financing Receivable, Nonaccrual	7,333	7,333	16,705
Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,958,766	1,958,766	1,982,632
Financing Receivable, Nonaccrual	145	145	30
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,328,207	7,328,207	7,210,607
Financing Receivable, Nonaccrual	7,478	7,478	16,735
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	20,045,797	20,045,797	18,928,090
Financing Receivable, Nonaccrual	20,484	20,484	37,320
Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	6,858,285	6,858,285	7,047,541
Financing Receivable, Nonaccrual	69,093	69,093	70,038
Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,041,644	3,041,644	2,810,220
Financing Receivable, Nonaccrual	8,218	8,218	7,402
Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	698,112	698,112	664,252
Financing Receivable, Nonaccrual	8,299	8,299	8,378
Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	308,126	308,126	318,483
Financing Receivable, Nonaccrual	85	85	122
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,906,167	10,906,167	10,840,496
Financing Receivable, Nonaccrual	85,696	85,696	85,941
Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	30,794,122	30,794,122	29,565,335
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	11,553,383	11,553,383	10,552,756
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	1,149,736	1,149,736	1,140,607
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	12,703,119	12,703,119	11,693,363
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	5,347,918	5,347,918	5,174,879
Financial Asset, Not Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,958,600	1,958,600	1,982,581
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	7,306,518	7,306,518	7,157,460
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	20,009,637	20,009,637	18,850,823
Financial Asset, Not Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	6,776,508	6,776,508	6,962,610
Financial Asset, Not Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,019,413	3,019,413	2,787,967
Financial Asset, Not Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	685,548	685,548	651,248
Financial Asset, Not Past Due [Member] | Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	303,016	303,016	312,687
Financial Asset, Not Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,784,484	10,784,484	10,714,512
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	43,970	43,970	40,961
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	517	517	899
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	0	0	1,533
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	517	517	2,432
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	13,168	13,168	5,117
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	21	21	21
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	13,189	13,189	5,138
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	13,706	13,706	7,570
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	12,667	12,667	14,731
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	11,997	11,997	12,588
Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	4,059	4,059	4,181
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	1,540	1,540	1,892
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	30,264	30,264	33,391
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,002	5,002	35,841
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	554	554	361
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	101
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	554	554	462
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	1,022	1,022	31,274
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	0	0	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	1,022	1,022	31,274
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	1,576	1,576	31,736
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	16	16	162
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	2,016	2,016	2,262
Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	206	206	445
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	1,188	1,188	1,236
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	3,426	3,426	4,105
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	2,692	2,692	3,189
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	395	395	642
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	395	395	642
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	0	0	0
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	0	0	0
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	395	395	642
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	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity Line of Credit [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	2,297	2,297	2,547
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	$ 2,297	$ 2,297	$ 2,547