Debt - Schedule of Short-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Federal Home Loan Bank	$ 1,400	$ 2,550
Securities sold under agreements to repurchase	371	747
Total short-term borrowings	1,771	3,297
Cash collateral received		6
Non-cash collateral received		1
Unsecured debt
Short-term Debt [Line Items]
Federal Home Loan Bank	0	0
Securities sold under agreements to repurchase	0	0
Total short-term borrowings	0	0
Secured debt
Short-term Debt [Line Items]
Federal Home Loan Bank	1,400	2,550
Securities sold under agreements to repurchase	371	747
Total short-term borrowings	1,771	$ 3,297
Secured debt | US Treasury And Federal Agency Securities
Short-term Debt [Line Items]
Securities sold under agreements to repurchase	$ 371