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v3.25.3

Business and Basis of Presentation Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | Dec. 31, 2025 | Jun. 30, 2025 | Jun. 30, 2024 | Dec. 31, 2023
Derivative [Line Items] |  |  |  |  |  |  |  |  |
Stockholders' Equity Attributable to Noncontrolling Interest | $ 115,790 |  | $ 115,790 |  | $ 197,755 |  |  |  |
Preferred Stock, Shares Issued | 0 |  | 0 |  | 0 |  |  |  |
Redeemable Noncontrolling Interest, Equity, Carrying Amount | $ 188,247 | $ 203,696 | $ 188,247 | $ 203,696 | $ 140,860 |  | $ 190,347 | $ 17,079 | $ 17,079
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest | (271) | (1,776) | (1,012) | (857) |  |  |  |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders | (300) | (626) | (1,219) | (1,676) |  |  |  |  |
Redeemable Noncontrolling Interest, Equity, Redemption Value | 188,247 |  | 188,247 |  |  |  |  |  |
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest | (892) | 1,773 | (2,292) | 859 |  |  |  |  |
Noncontrolling Interest, Change in Redemption Value | (569) | (2,402) | (2,717) | (2,533) |  |  |  |  |
Temporary Equity, Accretion to Redemption Value, Adjustment | 569 | 2,402 | 2,717 | 2,533 |  |  |  |  |
Disposal Group, Including Discontinued Operation, Net Assets Held-For Sale | 0 |  | 0 |  |  |  |  |  |
Disposal Group, Including Discontinued Operation, Assets |  | 7,358,328 |  | 7,358,328 |  | $ 6,267,200 |  |  |
Disposal Group, Including Discontinued Operation, Liabilities | 0 |  | 0 |  |  | $ 5,887,685 |  |  |
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent | (80,890) | (9,386) | (163,288) | 28,936 |  |  |  |  |
Put / call option exercise | 0 | 0 | (1,815) | 0 |  |  |  |  |
Payment for Put/Call Option |  |  | 1,068 |  |  |  |  |  |
Payments to Noncontrolling Interests | 2,967 |  | (71,345) |  |  |  |  |  |
Discontinued Operations, Held-for-Sale or Disposed of by Sale | Ambac Assurance Corporation [Member] |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |
Disposal Group, Including Discontinued Operation, Consideration, Fair Value, Net | 407,300 |  | 407,300 |  | 399,727 |  |  |  |
Disposal Group, Including Discontinued Operation, Estimated Closing Costs | 7,098 |  | 7,098 |  | 7,235 |  |  |  |
Disposal Group, Including Discontinued Operation, Consideration, Fair Value, Net, After Allowance For Closing Costs | 400,202 |  | 400,202 |  | 392,492 |  |  |  |
Disposal Group, Including Discontinued Operation, Net Assets Held-For Sale | 1,002,719 |  | 1,002,719 |  | 962,637 |  |  |  |
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax |  |  | 687,613 |  | 570,145 |  |  |  |
Disposal Group, Including Discontinued Operation, Investment |  |  |  |  | 2,226,505 |  |  |  |
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents |  |  |  |  | 8,322 |  |  |  |
Disposal Group, Including Discontinued Operation, Premiums Receivable, Net |  |  |  |  | 217,096 |  |  |  |
Disposal Group, Including Discontinued Operation, Reinsurance Recoverable For Paid And Unpaid Claims And Claims Adjustments |  |  |  |  | 25,274 |  |  |  |
Disposal Group, Including Discontinued Operation, Prepaid Reinsurance Premiums |  |  |  |  | 79,074 |  |  |  |
Disposal Group, Including Discontinued Operation, Subrogation Recoverable |  |  |  |  | 113,962 |  |  |  |
Disposal Group, Including Discontinued Operation, Intangible Assets |  |  |  |  | 213,457 |  |  |  |
Disposal Group, Including Discontinued Operation, Other Assets |  |  |  |  | 49,396 |  |  |  |
Disposal Group, Including Discontinued Operation, Variable Interest Entity Assets |  |  |  |  | 3,904,259 |  |  |  |
Disposal Group, Including Discontinued Operation, Valuation Allowance On Assets Held-For-Sale |  |  |  |  | (570,145) |  |  |  |
Disposal Group, Including Discontinued Operation, Assets |  |  |  |  | 6,267,200 |  |  |  |
Disposal Group, Including Discontinued Operation, Unearned Premiums |  |  |  |  | 228,177 |  |  |  |
Disposal Group, Including Discontinued Operation, Liability for Claims and Claims Adjustment Expense |  |  |  |  | 577,167 |  |  |  |
Disposal Group, Including Discontinued Operation, Reinsurance Payable |  |  |  |  | 56,404 |  |  |  |
Disposal Group, Including Discontinued Operation, Liabilities, Long-Term Debt And Accrued Interest |  |  |  |  | 1,046,658 |  |  |  |
Disposal Group, Including Discontinued Operation, Other Liabilities |  |  |  |  | 105,772 |  |  |  |
Disposal Group, Including Discontinued Operation, Variable Interest Entity Liabilities |  |  |  |  | 3,873,507 |  |  |  |
Disposal Group, Including Discontinued Operation, Liabilities |  |  |  |  | $ 5,887,685 |  |  |  |
Disposal Group, Including Discontinued Operation, Revenue | (65,455) | (44,141) | (121,050) | (150,687) |  |  |  |  |
Disposal Group, Including Discontinued Operation, Operating Expense | $ (88,425) | $ (49,906) | (156,192) | $ (110,986) |  |  |  |  |
Retained Earnings [Member] |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |
Noncontrolling Interest, Change in Redemption Value |  |  | $ (12,992) |  |  |  |  |  |

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