Loans and Allowance for Credit Losses for Loans - Summary of Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 49,272,823	$ 48,799,711
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	10,757,857	9,931,400
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	28,683,374	29,644,958
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	26,166,116	26,530,225
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,517,258	3,114,733
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,795,395	5,632,516
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,036,197	3,590,837
Consumer loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	655,872	604,433
Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	411,599	329,702
Non-accrual loans collateralized	48,200	49,500
Collateral Pledged | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	109,903	131,898
Collateral Pledged | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	268,855	172,666
Collateral Pledged | Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	233,967	156,825
Collateral Pledged | Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	34,888	15,841
Collateral Pledged | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	29,896	23,797
Collateral Pledged | Consumer loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 2,945	$ 1,341