Expected Loss to be Paid (Recovered) - Net Economic Loss Development (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	$ 21	$ 49	$ 14	$ 60
RMBS | United States
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	(10)	(9)	(13)	(4)
RMBS | United States | First Lien
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	(2)	0	(3)	0
RMBS | United States | Second Lien
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	$ (8)	$ (9)	$ (10)	$ (4)