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v3.25.1

Business and Basis of Presentation Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 31, 2025 | Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2024 | Dec. 31, 2025 | Dec. 31, 2023
Derivative [Line Items] |  |  |  |  |  |
Stockholders' Equity Attributable to Noncontrolling Interest | $ 173,827 |  |  | $ 197,755 |  |
Preferred Stock, Shares Issued | 0 |  |  | 0 |  |
Redeemable Noncontrolling Interest, Equity, Carrying Amount | $ 185,417 | $ 17,079 |  | $ 140,860 |  | $ 17,079
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest | 258 | 703 |  |  |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders | (708) | (650) |  |  |  |
Redeemable Noncontrolling Interest, Equity, Redemption Value | 185,417 |  |  |  |  |
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest | (1,654) | (701) |  |  |  |
Noncontrolling Interest, Change in Redemption Value | (907) | 53 | $ 45 |  |  |
Temporary Equity, Accretion to Redemption Value, Adjustment | 907 | (53) |  |  |  |
Disposal Group, Including Discontinued Operation, Assets | 6,392,004 | 7,454,216 |  |  | $ 6,267,200 |
Disposal Group, Including Discontinued Operation, Liabilities | 6,003,908 |  |  |  | 5,887,685 |
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent | (30,247) | 24,140 |  |  |  |
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 | 409,759 |  |  | 399,727 |  |
Disposal Group, Including Discontinued Operation, Estimated Closing Costs | (7,535) |  |  | (7,235) |  |
Disposal Group, Including Discontinued Operation, Consideration, Fair Value, Net, After Allowance For Closing Costs | 402,224 |  |  |  | $ 392,492 |
Disposal Group, Including Discontinued Operation, Net Assets Held-For Sale | 986,866 |  |  | 962,637 |  |
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax | (14,496) |  |  | (570,145) |  |
Disposal Group, Including Discontinued Operation, Investment | 2,286,236 |  |  | 2,226,505 |  |
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents | 14,394 |  |  | 8,322 |  |
Disposal Group, Including Discontinued Operation, Premiums Receivable, Net | 218,049 |  |  | 217,096 |  |
Disposal Group, Including Discontinued Operation, Reinsurance Recoverable For Paid And Unpaid Claims And Claims Adjustments | 25,918 |  |  | 25,274 |  |
Disposal Group, Including Discontinued Operation, Prepaid Reinsurance Premiums | 76,681 |  |  | 79,074 |  |
Disposal Group, Including Discontinued Operation, Subrogation Recoverable | 113,636 |  |  | 113,962 |  |
Disposal Group, Including Discontinued Operation, Intangible Assets | 209,677 |  |  | 213,457 |  |
Disposal Group, Including Discontinued Operation, Other Assets | 42,632 |  |  | 49,396 |  |
Disposal Group, Including Discontinued Operation, Variable Interest Entity Assets | 3,989,423 |  |  | 3,904,259 |  |
Disposal Group, Including Discontinued Operation, Valuation Allowance On Assets Held-For-Sale | (584,642) |  |  | (570,145) |  |
Disposal Group, Including Discontinued Operation, Assets | 6,392,004 |  |  | 6,267,200 |  |
Disposal Group, Including Discontinued Operation, Unearned Premiums | 229,035 |  |  | 228,177 |  |
Disposal Group, Including Discontinued Operation, Liability for Claims and Claims Adjustment Expense | 601,411 |  |  | 577,167 |  |
Disposal Group, Including Discontinued Operation, Reinsurance Payable | 55,571 |  |  | 56,404 |  |
Disposal Group, Including Discontinued Operation, Liabilities, Long-Term Debt And Accrued Interest | 1,062,616 |  |  | 1,046,658 |  |
Disposal Group, Including Discontinued Operation, Other Liabilities | 100,988 |  |  | 105,772 |  |
Disposal Group, Including Discontinued Operation, Variable Interest Entity Liabilities | 3,954,287 |  |  | 3,873,507 |  |
Disposal Group, Including Discontinued Operation, Liabilities | 6,003,908 |  |  | 5,887,685 |  |
Disposal Group, Including Discontinued Operation, Revenue | 26,797 | 53,058 |  |  |  |
Disposal Group, Including Discontinued Operation, Restricted Cash | 60,593 |  |  | $ 57,754 |  |
Disposal Group, Including Discontinued Operation, Reclassification From AOCI At Closing | $ (132,778) |  |  |  |  |
Retained Earnings [Member] |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Noncontrolling Interest, Change in Redemption Value |  | $ 47 |  |  |  |

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