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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, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |
RMBS losses | $ (32) | $ (20) | $ (76) | $ (7)
RMBS | United States |  |  |  |
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |
RMBS losses | (39) | (28) | (32) | (17)
RMBS | United States | First Lien |  |  |  |
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |
RMBS losses | (14) | (14) | 4 | 11
RMBS | United States | Second Lien |  |  |  |
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |
RMBS losses | $ (25) | $ (14) | $ (36) | $ (28)

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