Loans and Allowance for Credit Losses Past Due Loan Status and Non-Accrual Loans by Portfolio Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Non- accrual	$ 178,204	$ 143,666
Total	19,695,199	18,325,350
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	88,293	38,977
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	16,242	8,659
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	14,559	8,453
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	19,397,901	18,125,595
Real estate - commercial mortgage
Financing Receivable, Past Due [Line Items]
Non- accrual	94,704	52,815
Total	7,554,509	7,279,080
Real estate - commercial mortgage \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	9,428	1,089
Real estate - commercial mortgage \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,884	1,750
Real estate - commercial mortgage \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,577	1,229
Real estate - commercial mortgage \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	7,446,916	7,222,197
Commercial and Industrial
Financing Receivable, Past Due [Line Items]
Non- accrual	29,804	30,141
Total	4,243,392	4,208,327
Commercial and Industrial \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	4,705	5,457
Commercial and Industrial \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	228	1,932
Commercial and Industrial \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	27	488
Commercial and Industrial \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	4,208,628	4,170,309
Real estate - residential mortgage
Financing Receivable, Past Due [Line Items]
Non- accrual	31,464	35,269
Total	4,574,228	3,846,750
Real estate - residential mortgage \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	45,625	22,957
Real estate - residential mortgage \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	9,825	2,920
Real estate - residential mortgage \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	10,133	4,130
Real estate - residential mortgage \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	4,477,181	3,781,474
Real-estate - home equity
Financing Receivable, Past Due [Line Items]
Non- accrual	7,093	8,671
Total	1,110,103	1,118,248
Real-estate - home equity \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	4,976	4,369
Real-estate - home equity \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	815	1,154
Real-estate - home equity \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,087	2,253
Real-estate - home equity \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	1,095,132	1,101,801
Real-estate - construction
Financing Receivable, Past Due [Line Items]
Non- accrual	1,456	901
Total	1,273,097	1,139,779
Real-estate - construction \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	17,181	1,318
Real-estate - construction \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,106	0
Real-estate - construction \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Real-estate - construction \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	1,252,354	1,137,560
Consumer
Financing Receivable, Past Due [Line Items]
Non- accrual	101	229
Total	633,666	464,657
Consumer \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	6,308	3,561
Consumer \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,384	876
Consumer \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	735	353
Consumer \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	625,138	459,638
Equipment lease financing, other and overdrafts
Financing Receivable, Past Due [Line Items]
Non- accrual	13,582	15,640
Total	306,204	268,509
Equipment lease financing, other and overdrafts \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	70	226
Equipment lease financing, other and overdrafts \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	27
Equipment lease financing, other and overdrafts \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Equipment lease financing, other and overdrafts \| Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	292,552	$ 252,616
US Government Insured Loan Program \| Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,200
US Government Insured Loan Program \| Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	3,400
US Government Insured Loan Program \| Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	$ 10,400