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Fair Value Measurements - Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Carrying Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Other invested assets | $ 850 | $ 850
9% Convertible Junior Subordinated Debentures | 21,086 | 21,086
Total financial liabilities | 663,178 | 662,810
Fair Value | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Other invested assets | 850 | 850
9% Convertible Junior Subordinated Debentures | 28,196 | 28,085
Total financial liabilities | $ 646,190 | 629,023
Senior Notes | 5.25% Senior Notes Due 2028 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Stated interest rate | 5.25% |
Senior Notes | 5.25% Senior Notes Due 2028 | Carrying Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Senior Notes Payable | $ 642,092 | 641,724
Senior Notes | 5.25% Senior Notes Due 2028 | Fair Value | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Senior Notes Payable | $ 617,994 | $ 600,938
9% Convertible Junior Subordinated Debentures |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Stated interest rate | 9.00% |

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