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Fair Value Measurements - Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands | Jun. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Carrying Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Other invested assets | $ 850 | $ 3,100
FHLB Advance | 0 | 155,000
9% Convertible Junior Subordinated Debentures | 35,339 | 110,204
Total financial liabilities | 917,911 | 1,146,712
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 | 3,100
FHLB Advance | 0 | 157,585
9% Convertible Junior Subordinated Debentures | 47,197 | 151,000
Total financial liabilities | $ 878,432 | 1,251,673
Senior Notes | 5.75% Senior Notes Due 2023 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Stated interest rate | 5.75% |
Senior Notes | 5.75% Senior Notes Due 2023 | Carrying Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Senior Notes Payable | $ 241,583 | 241,255
Senior Notes | 5.75% Senior Notes Due 2023 | Fair Value | Significant Other Observable Inputs (Level 2) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Senior Notes Payable | $ 248,191 | 256,213
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 | $ 640,989 | 640,253
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 | $ 583,044 | $ 686,875
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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