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Outstanding Exposure - Schedule of Non-Financial Guaranty Exposure (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Diversified real estate |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Specialty business, gross par | $ 2,004 | $ 1,569
Specialty business, net par | 2,004 | 1,569
Insurance securitizations |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Specialty business, gross par | 1,449 | 1,370
Specialty business, net par | 1,126 | 1,043
Pooled corporate obligations |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Specialty business, gross par | 868 | 488
Specialty business, net par | 868 | 488
Aircraft residual value insurance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Specialty business, gross par | 147 | 355
Specialty business, net par | 87 | $ 200
Maximum | Insurance securitizations |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Specialty business, gross par | 1,500 |
Specialty business, net par | $ 1,200 |

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