Loans and Allowance for Credit Losses Past Due Loan Status and Non-Accrual Loans by Portfolio Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Total	$ 24,176,075	$ 21,351,094
Non- accrual	175,861	121,620
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	111,927	80,007
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	32,423	18,850
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	26,286	31,721
Current
Financing Receivable, Past Due [Line Items]
Total	23,829,578	21,098,896
Real estate - commercial mortgage
Financing Receivable, Past Due [Line Items]
Total	9,493,479	8,127,728
Non- accrual	69,386	44,805
Real estate - commercial mortgage \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	37,045	4,408
Real estate - commercial mortgage \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	13,818	1,341
Real estate - commercial mortgage \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,081	1,722
Real estate - commercial mortgage \| Current
Financing Receivable, Past Due [Line Items]
Total	9,371,149	8,075,452
Commercial and Industrial
Financing Receivable, Past Due [Line Items]
Total	4,914,734	4,545,552
Non- accrual	63,614	39,952
Commercial and Industrial \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	20,795	5,620
Commercial and Industrial \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	5,066	1,656
Commercial and Industrial \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	836	1,068
Commercial and Industrial \| Current
Financing Receivable, Past Due [Line Items]
Total	4,824,423	4,497,256
Real estate - residential mortgage
Financing Receivable, Past Due [Line Items]
Total	6,302,624	5,325,923
Non- accrual	24,431	20,824
Real estate - residential mortgage \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	41,105	49,145
Real estate - residential mortgage \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	9,022	10,838
Real estate - residential mortgage \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	17,296	21,205
Real estate - residential mortgage \| Current
Financing Receivable, Past Due [Line Items]
Total	6,210,770	5,223,911
Real estate - home equity
Financing Receivable, Past Due [Line Items]
Total	1,144,402	1,047,184
Non- accrual	8,047	4,753
Real estate - home equity \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	3,893	8,142
Real estate - home equity \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,320	2,075
Real estate - home equity \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	3,860	5,326
Real estate - home equity \| Current
Financing Receivable, Past Due [Line Items]
Total	1,127,282	1,026,888
Real-estate - construction
Financing Receivable, Past Due [Line Items]
Total	1,332,954	1,239,075
Non- accrual	340	1,341
Real-estate - construction \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,533	4,185
Real-estate - construction \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	832	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	1,327,843	1,231,563
Consumer
Financing Receivable, Past Due [Line Items]
Total	651,717	729,318
Non- accrual	209	52
Consumer \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	6,082	8,361
Consumer \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,992	1,767
Consumer \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	714	747
Consumer \| Current
Financing Receivable, Past Due [Line Items]
Total	642,720	718,391
Leases and other loans
Financing Receivable, Past Due [Line Items]
Total	336,165	336,314
Non- accrual	9,834	9,893
Leases and other loans \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	474	146
Leases and other loans \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	373	722
Leases and other loans \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	93	118
Leases and other loans \| Current
Financing Receivable, Past Due [Line Items]
Total	$ 325,391	$ 325,435