Loans and Allowance for Credit Losses for Loans - Schedule of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 34,153,657	$ 32,217,112
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,847,551	6,861,708
Loans, deferred income, PPP	12,100	43,200
Commercial and industrial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,411,601	4,709,569
Commercial and industrial | Commercial and industrial PPP loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	435,950	2,152,139
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	20,790,066	18,470,823
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	18,935,486	16,724,998
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,854,580	1,745,825
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,545,064	4,183,743
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,970,976	2,700,838
Consumer | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	400,779	431,553
Consumer | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,570,036	1,355,955
Consumer | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,000,161	$ 913,330