Loans Past Due Status (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2025	Jun. 30, 2024	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	$ 30,294,127		$ 29,768,586
Financing Receivable, Nonaccrual	134,808		123,260
Nonaccrual Loans, Current Portion	$ 44,000		$ 52,000
Percent of current nonaccrual loans	32.00%		42.00%
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0
Financing Receivable, Nonaccrual, No Allowance	23,000		$ 24,000
Commercial and Industrial Sector
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,925,769		10,573,741
Financing Receivable, Nonaccrual	12,898		19,084
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,118,363		1,143,741
Financing Receivable, Nonaccrual	1,501		1,501
Commercial And Business Lending [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	12,044,132		11,717,483
Financing Receivable, Nonaccrual	14,399		20,585
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	5,597,442		5,227,975
Financing Receivable, Nonaccrual	31,689		16,705
Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	1,809,054		1,982,632
Financing Receivable, Nonaccrual	125		30
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	7,406,496		7,210,607
Financing Receivable, Nonaccrual	31,814		16,735
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	19,450,628		18,928,090
Financing Receivable, Nonaccrual	46,213		37,320
Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	6,999,654		7,047,541
Financing Receivable, Nonaccrual	72,455		70,038
Automobile Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	2,878,765		2,810,220
Financing Receivable, Nonaccrual	7,692		7,402
Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	654,140		664,252
Financing Receivable, Nonaccrual	8,275		8,378
Other Consumer [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	310,940		318,483
Financing Receivable, Nonaccrual	173		122
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	10,843,499		10,840,496
Financing Receivable, Nonaccrual	88,595		85,941
Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Net of Deferred Income, Total	30,112,848		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	10,904,616		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	1,115,706		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	12,020,322		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	5,563,289		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	1,808,929		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	7,372,218		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	19,392,540		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	6,913,632		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	2,858,551		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	642,260		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	305,865		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	10,720,308		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	38,827		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	6,934		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	1,156		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	8,090		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	2,463		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	0		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	2,463		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	10,553		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	13,257		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	10,858		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	2,829		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	1,330		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	28,274		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	4,608		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	806		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		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	806		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	0		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
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	0		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	806		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	311		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	1,664		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	777		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	1,050		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	3,802		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	3,036		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	515		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
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	515		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
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	515		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
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
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	2,521		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	$ 2,521		$ 2,547