Loans and Allowance for Credit Losses Past Due Loan Status and Non-Accrual Loans by Portfolio Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Total	$ 24,106,297	$ 21,351,094
Non- accrual	145,630	121,620
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	110,932	80,007
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	34,377	18,850
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	26,962	31,721
Current
Financing Receivable, Past Due [Line Items]
Total	23,788,397	21,098,896
Real estate - commercial mortgage
Financing Receivable, Past Due [Line Items]
Total	9,289,770	8,127,728
Non- accrual	46,193	44,805
Real estate - commercial mortgage \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	14,262	4,408
Real estate - commercial mortgage \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,126	1,341
Real estate - commercial mortgage \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,422	1,722
Real estate - commercial mortgage \| Current
Financing Receivable, Past Due [Line Items]
Total	9,225,767	8,075,452
Commercial and Industrial
Financing Receivable, Past Due [Line Items]
Total	4,967,796	4,545,552
Non- accrual	57,274	39,952
Commercial and Industrial \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	12,191	5,620
Commercial and Industrial \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	14,984	1,656
Commercial and Industrial \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,159	1,068
Commercial and Industrial \| Current
Financing Receivable, Past Due [Line Items]
Total	4,882,188	4,497,256
Real estate - residential mortgage
Financing Receivable, Past Due [Line Items]
Total	6,248,856	5,325,923
Non- accrual	24,462	20,824
Real estate - residential mortgage \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	58,454	49,145
Real estate - residential mortgage \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	13,895	10,838
Real estate - residential mortgage \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	16,571	21,205
Real estate - residential mortgage \| Current
Financing Receivable, Past Due [Line Items]
Total	6,135,474	5,223,911
Real estate - home equity
Financing Receivable, Past Due [Line Items]
Total	1,120,878	1,047,184
Non- accrual	6,338	4,753
Real estate - home equity \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	7,403	8,142
Real estate - home equity \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,776	2,075
Real estate - home equity \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	4,880	5,326
Real estate - home equity \| Current
Financing Receivable, Past Due [Line Items]
Total	1,100,482	1,026,888
Real-estate - construction
Financing Receivable, Past Due [Line Items]
Total	1,463,799	1,239,075
Non- accrual	1,226	1,341
Real-estate - construction \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	10,951	4,185
Real-estate - construction \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	749	451
Real-estate - construction \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,406	1,535
Real-estate - construction \| Current
Financing Receivable, Past Due [Line Items]
Total	1,449,467	1,231,563
Consumer
Financing Receivable, Past Due [Line Items]
Total	692,086	729,318
Non- accrual	183	52
Consumer \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	7,274	8,361
Consumer \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,767	1,767
Consumer \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	485	747
Consumer \| Current
Financing Receivable, Past Due [Line Items]
Total	682,377	718,391
Leases and other loans
Financing Receivable, Past Due [Line Items]
Total	323,112	336,314
Non- accrual	9,954	9,893
Leases and other loans \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	397	146
Leases and other loans \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	80	722
Leases and other loans \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	39	118
Leases and other loans \| Current
Financing Receivable, Past Due [Line Items]
Total	$ 312,642	$ 325,435