Loans and Allowance for Credit Losses for Loans - Summary of Collateral Dependent Loans (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
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
Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	447,583	416,153
Non-accrual loans collateralized	42,500	47,100
Collateral Pledged \| Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	164,930	159,594
Collateral Pledged \| Commercial real estate \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	250,548	225,982
Collateral Pledged \| Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	29,483	28,569
Collateral Pledged \| Consumer loans \| Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 2,622	$ 2,008