Loans and Allowance for Credit Losses for Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 49,391,420	$ 48,799,711
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	10,870,036	9,931,400
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	28,825,920	29,644,958
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	25,971,061	26,530,225
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,854,859	3,114,733
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,709,971	5,632,516
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,985,493	3,590,837
Consumer loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	634,553	604,433
Consumer loans | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,178,841	1,901,065
Consumer loans | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,172,099	$ 1,085,339