Expected Loss to be Paid (Recovered) - Net Expected Loss to be Paid (Recovered) and Net Economic Loss Development (Benefit) by Accounting Model (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	$ 106	$ 505	$ 522	$ 411
Net Economic Loss Development (Benefit)	(3)	164	(125)
Insurance (see Note 5)
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	90	263
Net Economic Loss Development (Benefit)	(1)	174	(112)
FG VIEs (see Note 8)
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	16	240
Net Economic Loss Development (Benefit)	(1)	(11)	(17)
Credit derivatives (see Note 6)
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	0	2
Net Economic Loss Development (Benefit)	$ (1)	$ 1	$ 4