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Fair Value Measurements - Carrying Values and Estimated Fair Values of Financial Liabilities (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt | $ 503,305 | $ 503,946
Long-term debt, fair value | 497,298 | 503,805
Finance lease obligations | $ 1,909 | 2,636
7.25% Senior Notes |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Interest rate | 7.25% |
Long-term debt, fair value | $ 51,137 | 53,047
7.25% Senior Notes | Carrying Amount |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt | $ 49,927 | 49,926
6.70% Senior Notes |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Interest rate | 6.70% |
Long-term debt, fair value | $ 101,666 | 104,039
6.70% Senior Notes | Carrying Amount |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt | $ 99,571 | 99,565
5.375% Senior Notes |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Interest rate | 5.375% |
Long-term debt, fair value | $ 286,927 | 288,787
5.375% Senior Notes | Carrying Amount |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt | $ 294,548 | 294,523
3.03% borrowings from FHLBI |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Interest rate | 3.03% |
Long-term debt, fair value | $ 57,568 | 57,932
3.03% borrowings from FHLBI | Carrying Amount |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt | 60,000 | 60,000
Long Term Debt Excluding Issuance Costs and Finance Lease Obligations |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt, fair value | 497,298 | 503,805
Long Term Debt Excluding Issuance Costs and Finance Lease Obligations | Carrying Amount |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt | 504,046 | 504,014
Unamortized Debt Issuance Costs | Carrying Amount |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Unamortized debt issuance costs | $ (2,650) | $ (2,704)

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