Securities - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($) security	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) security	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) security
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of available-for-sale debt securities in an unrealized loss position | security	446		446		541
Debt securities, available-for-sale, allowance for credit loss	$ 3,000,000		$ 3,000,000		$ 0
Allowance for credit losses on available-for-sale debt securities	3,000,000	$ 0	3,000,000	$ 0
Allowance for Credit Losses	0		0		0
Asset Pledged as Collateral
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
AFS and HTM debt securities carrying value	4,400,000,000		4,400,000,000		$ 5,400,000,000
Prepositioned for Federal Reserve Bank Standing Repurchase Agreement Facility
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
AFS and HTM debt securities carrying value	$ 2,500,000,000		$ 2,500,000,000
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of available-for-sale debt securities in an unrealized loss position | security	228		228		290
Non-agency mortgage-backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of available-for-sale debt securities in an unrealized loss position | security	71		71		83
Debt securities, available-for-sale, allowance for credit loss	$ 3,000,000		$ 3,000,000
Allowance for credit losses on available-for-sale debt securities	$ 3,000,000		$ 3,000,000
Corporate debt securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of available-for-sale debt securities in an unrealized loss position | security	53		53		66
Debt securities, available-for-sale, allowance for credit loss	$ 0		$ 0