Loans and Allowance for Credit Losses for Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 45,185,764	$ 34,153,657
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	8,701,377	5,847,551
Loans, deferred income, PPP	1,400	12,100
Commercial and industrial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	8,615,557	5,411,601
Commercial and industrial | Commercial and industrial PPP loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	85,820	435,950
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	28,065,263	20,790,066
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	24,493,445	18,935,486
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,571,818	1,854,580
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,177,128	4,545,064
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,241,996	2,970,976
Consumer | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	467,135	400,779
Consumer | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,711,086	1,570,036
Consumer | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,063,775	$ 1,000,161