Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	$ 31,798,164	$ 31,163,614
Financing Receivable, Nonaccrual	110,581	100,428
Nonaccrual Loans, Current Portion	$ 45,600	$ 31,200
Percent of current nonaccrual loans	41.00%	31.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	13,200	14,600
Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	12,339,597	11,799,757
Financing Receivable, Nonaccrual	19,606	7,178
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,193,778	1,186,324
Financing Receivable, Nonaccrual	34	203
Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	13,533,375	12,986,081
Financing Receivable, Nonaccrual	19,640	7,381
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,266,584	5,246,030
Financing Receivable, Nonaccrual	8,078	8,311
Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,117,479	1,994,642
Financing Receivable, Nonaccrual	25	144
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,384,063	7,240,672
Financing Receivable, Nonaccrual	8,103	8,455
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	20,917,438	20,226,753
Financing Receivable, Nonaccrual	27,743	15,836
Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	6,727,734	6,793,957
Financing Receivable, Nonaccrual	66,890	68,492
Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,136,334	3,106,498
Financing Receivable, Nonaccrual	8,888	8,271
Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	706,075	713,271
Financing Receivable, Nonaccrual	6,950	7,774
Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	310,583	323,135
Financing Receivable, Nonaccrual	110	55
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,880,726	10,936,861
Financing Receivable, Nonaccrual	82,838	84,592
Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	31,599,789	31,002,071
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	12,295,353	11,789,526
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	1,193,399	1,186,087
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	13,488,752	12,975,613
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	5,225,019	5,218,314
Financial Asset, Not Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,117,454	1,994,381
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	7,342,473	7,212,695
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	20,831,225	20,188,308
Financial Asset, Not Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	6,653,089	6,712,330
Financial Asset, Not Past Due [Member] | Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	3,112,886	3,081,782
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	696,383	701,719
Financial Asset, Not Past Due [Member] | Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	306,206	317,932
Financial Asset, Not Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,768,564	10,813,763
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	80,821	48,311
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	24,050	2,153
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	345	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	24,395	2,153
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	33,012	14,148
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	0	117
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	33,012	14,265
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	57,407	16,418
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	7,723	13,135
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	12,235	14,340
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	2,159	2,945
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	1,297	1,473
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	23,414	31,893
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	4,483	9,990
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	203	530
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	34
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	203	564
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	475	5,257
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
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	475	5,257
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	678	5,821
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	32	0
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	2,314	2,105
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	583	833
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	876	1,231
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	3,805	4,169
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	2,490	2,814
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	385	370
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
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	385	370
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
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
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
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	385	370
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
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	11	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
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	2,094	2,444
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	$ 2,105	$ 2,444