Loans and Allowance for Credit Losses for Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 48,657,128	$ 48,799,711
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	10,150,205	9,931,400
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	29,114,556	29,644,958
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	26,087,621	26,530,225
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,026,935	3,114,733
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,636,407	5,632,516
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,755,960	3,590,837
Consumer loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	602,161	604,433
Consumer loans | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,041,227	1,901,065
Consumer loans | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,112,572	$ 1,085,339