Securities - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, allowance for credit loss, excluding accrued interest	$ 0	$ 0	$ 0
Debt securities, available-for-sale, accrued interest, after allowance for credit loss	$ 10,400,000		$ 9,200,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other assets		Other assets
Debt securities, available-for-sale, accrued interest writeoff	$ 0	0
Debt securities, held-to-maturity, allowance for credit loss, excluding accrued interest	0	0	$ 0
Debt securities, held-to-maturity, accrued interest, after allowance for credit loss	$ 900,000		$ 900,000
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other assets		Other assets
Debt securities, held-to-maturity, accrued interest, writeoff	$ 0	$ 0
Deposit liabilities, collateral issued, financial instruments	604,000,000		$ 615,700,000
Bank Term Funding Program
Debt Securities, Available-for-sale [Line Items]
Deposit liabilities, collateral issued, financial instruments	0		2,400,000,000
Federal Reserve Discount Window
Debt Securities, Available-for-sale [Line Items]
Deposit liabilities, collateral issued, financial instruments	$ 2,600,000,000		$ 168,800,000