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Significant Transactions - Bamboo (Details) - USD ($) $ in Millions |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 05, 2025 | Jan. 02, 2024 | Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Mar. 31, 2024
Other Significant Transactions [Line Items] |  |  |  |  |  |
Net cash proceeds |  |  | $ 746.5 | $ 0.0 | $ 17.3 |
Common equity securities, at fair value |  |  | 483.0 | 650.0 |  |
Net gain on sale of the Bamboo Group |  |  | 849.3 | $ 0.0 | $ 0.0 |
Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Net gain on sale of the Bamboo Group |  |  | 33.0 |  |  |
Bamboo Group | Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Net cash proceeds | $ 847.9 |  |  |  |  |
Proceeds held in escrow |  |  | 3.6 |  |  |
Net gain |  |  | 816.3 |  |  |
Net gain on sale of the Bamboo Group |  |  | $ 849.3 |  |  |
Variable Interest Entity, Not Primary Beneficiary | Bamboo SPV |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Ownership interest |  |  | 27.90% |  |  |
Bamboo Ide8 Insurance Services LLC |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Contributions to subsidiaries |  | $ 296.7 |  |  |  |
Contributions to retire credit facility |  | 36.0 |  |  |  |
Cash contributions for transaction |  | $ 20.0 |  |  |  |
Basic ownership |  | 72.80% |  |  |  |
Ownership percentage, after equity incentives |  | 63.70% |  |  |  |
Assets and goodwill acquired |  | $ 479.5 |  |  |  |
Liabilities acquired |  | 91.7 |  |  |  |
Noncontrolling interest acquired |  | 111.1 |  |  |  |
Assets including goodwill |  | 371.4 |  |  |  |
Transaction costs |  | $ 4.0 |  |  |  | $ 0.3
Bamboo Ide8 Insurance Services LLC | Bamboo Management |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Basic ownership |  | 16.10% |  |  |  |
Ownership percentage, after equity incentives |  | 26.60% |  |  |  |
Bamboo Group |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Basic ownership |  |  | 17.20% |  |  |
Equity interest percent of ownership sold | 77.30% |  |  |  |  |
Common equity securities, at fair value | $ 250.0 |  |  |  |  |
Ownership percentage, fully diluted |  |  | 14.60% |  |  |
Bamboo Group | Bamboo Group | Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |  |  |  |
Other Significant Transactions [Line Items] |  |  |  |  |  |
Net gain on sale of the Bamboo Group |  |  | $ 188.6 |  |  |

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