Loans and Allowance for Credit Losses for Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 52,467,251	$ 50,136,728
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	11,961,242	10,961,519
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	30,348,835	29,243,982
Commercial real estate \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	27,873,726	26,772,749
Commercial real estate \| Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,475,109	2,471,233
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,982,941	5,826,192
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,174,233	4,105,035
Consumer loans \| Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	728,623	687,680
Consumer loans \| Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,150,089	2,184,600
Consumer loans \| Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,295,521	$ 1,232,755