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Expected Loss to be Paid (Recovered) - Net Expected Loss to be Paid After Net Expected Recoveries for Breaches of R&W Rollforward (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | $ 560 | $ 442 | $ 522 | $ 411 | $ 411
Accretion of discount | 6 | 3 | 15 | 8 |
Changes in discount rates | (12) | (25) | (8) | (114) |
Changes in timing and assumptions | 93 | (50) | 140 | (42) |
Total economic loss development (benefit) | 87 | (72) | 147 | (148) |
Net (paid) recovered losses | (157) | 357 | (179) | 464 |
Net expected loss to be paid (recovered), end of period | 490 | 727 | $ 490 | 727 | $ 522
Weighted average risk free discount rate |  |  | 4.80% |  | 4.08%
Period after the end of the reporting period within which the ceded paid losses are typically settled (in days) |  |  | 45 days |  |
Minimum |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Risk free discount rate |  |  | 4.51% |  | 3.82%
Maximum |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Risk free discount rate |  |  | 5.45% |  | 4.69%
United States |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid after recoveries for representations and warranties, percent |  |  | 98.20% |  | 98.50%
Public finance |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | 443 | 217 | $ 412 | 209 | $ 209
Total economic loss development (benefit) | 134 | 22 | 193 | (22) |
Net (paid) recovered losses | (169) | 393 | (197) | 445 |
Net expected loss to be paid (recovered), end of period | 408 | 632 | 408 | 632 | 412
Public finance | United States |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | 433 | 210 | 403 | 197 | 197
Total economic loss development (benefit) | 135 | 24 | 193 | (16) |
Net (paid) recovered losses | (169) | 392 | (197) | 445 |
Net expected loss to be paid (recovered), end of period | 399 | 626 | 399 | 626 | 403
Public finance | Non-U.S. public finance |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | 10 | 7 | 9 | 12 | 12
Total economic loss development (benefit) | (1) | (2) | 0 | (6) |
Net (paid) recovered losses | 0 | 1 | 0 | 0 |
Net expected loss to be paid (recovered), end of period | 9 | 6 | 9 | 6 | 9
RMBS | United States |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | 73 | 179 | 66 | 150 | 150
Total economic loss development (benefit) | (48) | (95) | (52) | (127) |
Net (paid) recovered losses | 13 | (32) | 24 | 29 |
Net expected loss to be paid (recovered), end of period | 38 | 52 | 38 | 52 | 66
Other structured finance |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | 44 | 46 | 44 | 52 | 52
Total economic loss development (benefit) | 1 | 1 | 6 | 1 |
Net (paid) recovered losses | (1) | (4) | (6) | (10) |
Net expected loss to be paid (recovered), end of period | 44 | 43 | 44 | 43 | 44
Structured finance |  |  |  |  |
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward] |  |  |  |  |
Net expected loss to be paid (recovered), beginning of period | 117 | 225 | 110 | 202 | 202
Total economic loss development (benefit) | (47) | (94) | (46) | (126) |
Net (paid) recovered losses | 12 | (36) | 18 | 19 |
Net expected loss to be paid (recovered), end of period | $ 82 | $ 95 | $ 82 | $ 95 | $ 110

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