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v3.26.1

Outstanding Exposure - Components of BIG Net Par Outstanding (Details) - USD ($) $ in Millions | Mar. 31, 2026 | Dec. 31, 2025
--- | --- | ---
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 278,600 | $ 277,100
Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 265,900 | 265,600
Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 12,700 | 11,500
BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 8,640 | 8,760
BIG | BIG 1 |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,630 | 3,740
BIG | BIG 1 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,450 | 3,570
BIG | BIG 1 | Other structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 0 | 0
BIG | BIG 1 | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 180 | 170
BIG | BIG 2 |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,830 | 3,810
BIG | BIG 2 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,790 | 3,770
BIG | BIG 2 | Other structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 20 | 10
BIG | BIG 2 | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 40 | 40
BIG | BIG 3 |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 1,180 | 1,210
BIG | BIG 3 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 580 | 580
BIG | BIG 3 | Other structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 50 | 60
BIG | BIG 3 | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 600 | 630
BIG | Total BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 8,640 | 8,760
BIG | Total BIG | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 7,820 | 7,920
BIG | Total BIG | Other structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 70 | 70
BIG | Total BIG | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 820 | 840
United States | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 216,400 | 215,000
United States | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 8,300 | 7,900
United States | BIG | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,400 | 3,500
United States | BIG | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 800 | 900
United States | BIG | BIG 1 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 2,410 | 2,480
United States | BIG | BIG 1 | RMBS |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 180 | 170
United States | BIG | BIG 2 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 470 | 420
United States | BIG | BIG 2 | RMBS |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 20 | 30
United States | BIG | BIG 3 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 580 | 580
United States | BIG | BIG 3 | RMBS |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 550 | 570
United States | BIG | Total BIG | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,460 | 3,480
United States | BIG | Total BIG | RMBS |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 750 | 770
Non-U.S. public finance | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 49,500 | 50,600
Non-U.S. public finance | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 4,400 | 3,600
Non-U.S. public finance | BIG | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 4,400 | 4,400
Non-U.S. public finance | BIG | Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 0 | 0
Non-U.S. public finance | BIG | BIG 1 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 1,040 | 1,090
Non-U.S. public finance | BIG | BIG 2 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 3,320 | 3,350
Non-U.S. public finance | BIG | BIG 3 | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | 0 | 0
Non-U.S. public finance | BIG | Total BIG | Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 4,360 | $ 4,440

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