Loans and Allowance for Credit Losses for Loans - Summary of Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 50,210,295	$ 46,917,200
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	9,230,543	8,804,830
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	31,970,047	29,432,868
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	28,243,239	25,732,033
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,726,808	3,700,835
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,569,010	5,364,550
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,440,695	3,314,952
Home equity | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	559,152	503,884
Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	264,678	258,692
Collateral Pledged | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	96,827	94,433
Collateral Pledged | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	145,419	130,199
Collateral Pledged | Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	98,785	74,855
Collateral Pledged | Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	46,634	55,344
Collateral Pledged | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	21,843	33,865
Collateral Pledged | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	589	0
Collateral Pledged | Home equity | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 0	$ 195