Fair Value - Recurring Level 3 Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Available-for-Sale Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 514	$ 634	$ 753
Purchases	0	0	0
Sales	0	0	0
Issuances	0	0	0
Settlements	(92)	(124)	(90)
Net transfers	1	0	1
Total gains (losses) realized & unrealized	6	4	(28)
Ending Balance	427	514	634
Mortgage Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	477	543	755
Purchases	0	0	0
Sales	(14)	(1)	(4)
Issuances	0	0	0
Settlements	(63)	(79)	(135)
Net transfers	9	(2)	6
Total gains (losses) realized & unrealized	8	12	(67)
Ending Balance	399	477	543
Net Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	77	(37)	131
Purchases	0	0	0
Sales	0	0	0
Issuances	0	0	0
Settlements	54	36	36
Net transfers	0	0	0
Total gains (losses) realized & unrealized	(92)	78	(204)
Ending Balance	39	77	(37)
Long-term Debt
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(385)	(378)	(468)
Purchases	0	0	0
Sales	0	0	0
Issues	0	0	(86)
Settlements	16	17	39
Net transfers	0	1	0
Total gains (losses) realized & unrealized	16	(25)	137
Ending Balance	(353)	(385)	(378)
Mortgage-related securities | Trading Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	26	47	57
Purchases	0	0	0
Sales	0	0	0
Issuances	0	0	0
Settlements	(1)	(1)	(1)
Net transfers	(3)	11	1
Total gains (losses) realized & unrealized	0	(9)	(8)
Ending Balance	$ 28	$ 26	$ 47