Loans and Allowance for Credit Losses for Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 48,659,966	$ 46,917,200
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	9,043,946	8,804,830
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	30,777,078	29,432,868
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	27,051,111	25,732,033
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,725,967	3,700,835
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,486,280	5,364,550
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,352,662	3,314,952
Consumer | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	516,592	503,884
Consumer | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,717,141	1,746,225
Consumer | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,118,929	$ 1,064,843