Fair Value - Level 3 Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Available-for-Sale Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 405	$ 487	$ 427	$ 514
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(17)	(18)	(36)	(55)
Net transfers	0	(1)	0	(1)
Total gains (losses) realized & unrealized	11	(7)	8	3
Ending Balance	399	461	399	461
Mortgage Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	388	470	399	477
Purchases	0	0	0	0
Sales	0	(2)	0	(6)
Issuances	0	0	0	0
Settlements	(13)	(16)	(29)	(33)
Net transfers	1	(23)	(1)	(10)
Total gains (losses) realized & unrealized	0	(4)	7	(3)
Ending Balance	376	425	376	425
Net Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	35	69	39	77
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	18	25	19	29
Net transfers	0	0	0	0
Total gains (losses) realized & unrealized	(20)	0	(25)	(12)
Ending Balance	33	94	33	94
Long-term Debt
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(364)	(387)	(353)	(385)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	2	3	6	7
Net transfers	0	1	0	1
Total gains (losses) realized & unrealized	12	3	(3)	(3)
Ending Balance	(350)	(380)	(350)	(380)
Mortgage-related securities | Trading Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	26	28	28	26
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Net transfers	0	4	(3)	7
Total gains (losses) realized & unrealized	(1)	0	0	(1)
Ending Balance	$ 25	$ 32	$ 25	$ 32