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Investment Funds (Details) - USD ($) $ in Thousands |  | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | ---
Jul. 01, 2022 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021 | Dec. 31, 2021
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Unfunded commitments |  | $ 538,000 |  | $ 538,000 |  |
Investment funds |  | 1,662,029 |  | 1,662,029 |  | $ 1,480,612
Income from Investment Funds |  |  |  | 121,919 | $ 169,538 |
Written premiums ceded |  | 504,664 | $ 462,360 | $ 1,418,012 | 1,346,089 |
Lifson Re |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Percentage of reinsurance placements of share placed amounts | 30.00% |  |  | 22.50% |  |
Written premiums ceded |  |  |  | $ 308,000 | 182,000 |
Financial services |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Investment funds |  | 225,242 |  | 225,242 |  | 273,690
Income from Investment Funds |  |  |  | 42,708 | 18,497 |
Transportation |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Investment funds |  | 467,954 |  | 467,954 |  | 431,818
Income from Investment Funds |  |  |  | 27,472 | 83,455 |
Real Estate |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Investment funds |  | 346,755 |  | 346,755 |  | 336,688
Income from Investment Funds |  |  |  | 48,249 | 31,805 |
Energy |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Investment funds |  | 121,237 |  | 121,237 |  | 150,224
Income from Investment Funds |  |  |  | 1,966 | 14,065 |
Infrastructure |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Investment funds |  | 111,353 |  | 111,353 |  | 12,314
Income from Investment Funds |  |  |  | 1,277 | 1,154 |
Other funds |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Investment funds |  | 389,488 |  | 389,488 |  | 275,878
Income from Investment Funds |  |  |  | 247 | $ 20,562 |
Deferred compensation trust assets |  | $ 31,000 |  | $ 31,000 |  | $ 34,000

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