Securities - Narrative (Details)	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
AFS and HTM, accrued interest | $	$ 44,000,000	$ 42,000,000
Number of available-for-sale debt securities in an unrealized loss position | security	547	559
Allowance for credit loss | $	$ 0	$ 0
HTM securities allowance for credit loss | $	0	0
Asset Pledged as Collateral
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost | $	$ 7,000,000,000	$ 794,000,000
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	255	263
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	99	100
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	66	68