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Expected Loss to be Paid (Recovered) - Net Economic Loss Development (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	$ 49	$ (32)	$ 60	$ (76)
RMBS | United States
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	(9)	(39)	(4)	(32)
RMBS | United States | First Lien
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	0	(14)	0	4
RMBS | United States | Second Lien
Schedule of Expected Losses to be Paid [Line Items]
RMBS losses	$ (9)	$ (25)	$ (4)	$ (36)

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