Loans and Allowance for Credit Losses for Loans - Past Due, Non-Accrual and Current Loans by Loan Portfolio Class (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans	$ 45,185,764	$ 34,153,657
Non-Accrual Loans	293,395	240,216
Non-Accrual Loans Without Allowance for Loan Losses	98,745	100,190
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	392,144	296,080
30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	44,963	40,889
60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	22,661	12,204
90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	31,125	2,771
Current Loans
Financing Receivable, Past Due [Line Items]
Loans	44,793,620	33,857,577
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	8,701,377	5,847,551
Non-Accrual Loans	135,187	99,918
Non-Accrual Loans Without Allowance for Loan Losses	5,043	9,066
Commercial and industrial | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	171,973	115,778
Commercial and industrial | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	19,526	6,717
Commercial and industrial | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	2,188	7,870
Commercial and industrial | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	15,072	1,273
Commercial and industrial | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	8,529,404	5,731,773
Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans	28,065,263	20,790,066
Non-Accrual Loans	128,417	101,233
Non-Accrual Loans Without Allowance for Loan Losses	79,201	70,719
Commercial real estate | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	163,047	117,627
Commercial real estate | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	6,196	16,362
Commercial real estate | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	13,352	0
Commercial real estate | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	15,082	32
Commercial real estate | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	27,902,216	20,672,439
Commercial real estate | Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans	24,493,445	18,935,486
Non-Accrual Loans	67,319	83,592
Non-Accrual Loans Without Allowance for Loan Losses	64,260	70,719
Commercial real estate | Commercial real estate | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	88,980	98,045
Commercial real estate | Commercial real estate | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	6,196	14,421
Commercial real estate | Commercial real estate | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	383	0
Commercial real estate | Commercial real estate | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	15,082	32
Commercial real estate | Commercial real estate | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	24,404,465	18,837,441
Commercial real estate | Construction
Financing Receivable, Past Due [Line Items]
Loans	3,571,818	1,854,580
Non-Accrual Loans	61,098	17,641
Non-Accrual Loans Without Allowance for Loan Losses	14,941	0
Commercial real estate | Construction | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	74,067	19,582
Commercial real estate | Construction | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	0	1,941
Commercial real estate | Construction | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	12,969	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	3,497,751	1,834,998
Residential mortgage
Financing Receivable, Past Due [Line Items]
Loans	5,177,128	4,545,064
Non-Accrual Loans	26,564	35,207
Non-Accrual Loans Without Allowance for Loan Losses	14,378	20,401
Residential mortgage | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	46,106	50,197
Residential mortgage | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	13,045	10,999
Residential mortgage | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	5,947	3,314
Residential mortgage | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	550	677
Residential mortgage | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	5,131,022	4,494,867
Consumer
Financing Receivable, Past Due [Line Items]
Loans	3,241,996	2,970,976
Non-Accrual Loans	3,227	3,858
Non-Accrual Loans Without Allowance for Loan Losses	123	4
Consumer | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	11,018	12,478
Consumer | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	6,196	6,811
Consumer | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	1,174	1,020
Consumer | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	421	789
Consumer | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	3,230,978	2,958,498
Consumer | Home equity
Financing Receivable, Past Due [Line Items]
Loans	467,135	400,779
Non-Accrual Loans	2,845	3,517
Non-Accrual Loans Without Allowance for Loan Losses	123	4
Consumer | Home equity | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,646	3,857
Consumer | Home equity | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	321	242
Consumer | Home equity | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	168	98
Consumer | Home equity | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	312	0
Consumer | Home equity | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	463,489	396,922
Consumer | Automobile
Financing Receivable, Past Due [Line Items]
Loans	1,711,086	1,570,036
Non-Accrual Loans	286	240
Non-Accrual Loans Without Allowance for Loan Losses	0	0
Consumer | Automobile | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	6,096	7,558
Consumer | Automobile | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	4,999	6,391
Consumer | Automobile | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	702	656
Consumer | Automobile | 90 Days or More Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	109	271
Consumer | Automobile | Current Loans
Financing Receivable, Past Due [Line Items]
Loans	1,704,990	1,562,478
Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Loans	1,063,775	1,000,161
Non-Accrual Loans	96	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	1,276	1,063
Consumer | Other consumer | 30-59  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	876	178
Consumer | Other consumer | 60-89  Days  Past Due Loans
Financing Receivable, Past Due [Line Items]
Loans	304	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	$ 1,062,499	$ 999,098