Loans and Allowance for Credit Losses for Loans - Past Due, Non-Accrual and Current Loans by Loan Portfolio Class (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans	$ 43,560,777	$ 34,153,657
Non-Accrual Loans	313,117	240,216
Non-Accrual Loans Without Allowance for Loan Losses	99,285	100,190
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	386,618	296,080
30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	45,102	40,889
60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	11,474	12,204
90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	16,925	2,771
Current Loans
Financing Receivable, Past Due [Line Items]
Loans	43,174,159	33,857,577
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	8,514,458	5,847,551
Non-Accrual Loans	148,404	99,918
Non-Accrual Loans Without Allowance for Loan Losses	6,648	9,066
Commercial and industrial | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	174,887	115,778
Commercial and industrial | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	7,143	6,717
Commercial and industrial | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	3,870	7,870
Commercial and industrial | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	15,470	1,273
Commercial and industrial | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	8,339,571	5,731,773
Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans	26,909,459	20,790,066
Non-Accrual Loans	135,587	101,233
Non-Accrual Loans Without Allowance for Loan Losses	77,622	70,719
Commercial real estate | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	159,703	117,627
Commercial real estate | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	19,624	16,362
Commercial real estate | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	4,492	0
Commercial real estate | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	0	32
Commercial real estate | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	26,749,756	20,672,439
Commercial real estate | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans	23,535,086	18,935,486
Non-Accrual Loans	85,807	83,592
Non-Accrual Loans Without Allowance for Loan Losses	68,128	70,719
Commercial real estate | Commercial real estate | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	96,953	98,045
Commercial real estate | Commercial real estate | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	10,516	14,421
Commercial real estate | Commercial real estate | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	630	0
Commercial real estate | Commercial real estate | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	0	32
Commercial real estate | Commercial real estate | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	23,438,133	18,837,441
Commercial real estate | Construction
Financing Receivable, Past Due [Line Items]
Loans	3,374,373	1,854,580
Non-Accrual Loans	49,780	17,641
Non-Accrual Loans Without Allowance for Loan Losses	9,494	0
Commercial real estate | Construction | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	62,750	19,582
Commercial real estate | Construction | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	9,108	1,941
Commercial real estate | Construction | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	3,862	0
Commercial real estate | Construction | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	0	0
Commercial real estate | Construction | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	3,311,623	1,834,998
Residential mortgage
Financing Receivable, Past Due [Line Items]
Loans	5,005,069	4,545,064
Non-Accrual Loans	25,847	35,207
Non-Accrual Loans Without Allowance for Loan Losses	14,889	20,401
Residential mortgage | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	41,771	50,197
Residential mortgage | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	12,326	10,999
Residential mortgage | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	2,410	3,314
Residential mortgage | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	1,188	677
Residential mortgage | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	4,963,298	4,494,867
Consumer
Financing Receivable, Past Due [Line Items]
Loans	3,131,791	2,970,976
Non-Accrual Loans	3,279	3,858
Non-Accrual Loans Without Allowance for Loan Losses	126	4
Consumer | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	10,257	12,478
Consumer | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	6,009	6,811
Consumer | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	702	1,020
Consumer | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	267	789
Consumer | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	3,121,534	2,958,498
Consumer | Home equity
Financing Receivable, Past Due [Line Items]
Loans	431,455	400,779
Non-Accrual Loans	2,920	3,517
Non-Accrual Loans Without Allowance for Loan Losses	126	4
Consumer | Home equity | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,299	3,857
Consumer | Home equity | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	377	242
Consumer | Home equity | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	2	98
Consumer | Home equity | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	0	0
Consumer | Home equity | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	428,156	396,922
Consumer | Automobile
Financing Receivable, Past Due [Line Items]
Loans	1,673,482	1,570,036
Non-Accrual Loans	262	240
Non-Accrual Loans Without Allowance for Loan Losses	0	0
Consumer | Automobile | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,813	7,558
Consumer | Automobile | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	4,696	6,391
Consumer | Automobile | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	588	656
Consumer | Automobile | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	267	271
Consumer | Automobile | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	1,667,669	1,562,478
Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Loans	1,026,854	1,000,161
Non-Accrual Loans	97	101
Non-Accrual Loans Without Allowance for Loan Losses	0	0
Consumer | Other consumer | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,145	1,063
Consumer | Other consumer | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	936	178
Consumer | Other consumer | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	112	266
Consumer | Other consumer | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	0	518
Consumer | Other consumer | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	$ 1,025,709	$ 999,098