Debt - Schedule of Short-term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Short-term Debt [Line Items]
Federal Home Loan Bank	$ 2,450	$ 1,625
Securities sold under agreements to repurchase	889	0
Total short-term borrowings	3,339	1,625
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	2,450	1,625
Securities sold under agreements to repurchase	889	0
Total short-term borrowings	$ 3,339	$ 1,625