Loans and Allowance for Credit Losses for Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 49,355,319	$ 50,210,295
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	9,799,287	9,230,543
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	30,402,196	31,970,047
Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	26,914,732	28,243,239
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,487,464	3,726,808
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,684,079	5,569,010
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,469,757	3,440,695
Consumer loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	581,181	559,152
Consumer loans | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,823,738	1,620,389
Consumer loans | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,064,838	$ 1,261,154