Fair Value Measurements - Schedule of Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	$ 18,556	$ 21,923
Commercial mortgage loans, fair value	209,041	178,913
Long-term debt, fair value	491,369	503,805
Corporate securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	18,556	21,923
Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Commercial mortgage loans, fair value	0	0
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) | Corporate securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	18,556	21,923
Commercial mortgage loans, fair value	0	0
Long-term debt, fair value	491,369	503,805
Significant Other Observable Inputs (Level 2) | Corporate securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	18,556	21,923
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Commercial mortgage loans, fair value	209,041	178,913
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) | Corporate securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed income securities, held-to-maturity - fair value	$ 0	$ 0
7.25% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	7.25%	7.25%
Long-term debt, fair value	$ 51,301	$ 53,047
7.25% Senior Notes | Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
7.25% Senior Notes | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	51,301	53,047
7.25% Senior Notes | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 0	$ 0
6.70% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	6.70%	6.70%
Long-term debt, fair value	$ 99,393	$ 104,039
6.70% Senior Notes | Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
6.70% Senior Notes | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	99,393	104,039
6.70% Senior Notes | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 0	$ 0
5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	5.375%	5.375%
Long-term debt, fair value	$ 283,037	$ 288,787
5.375% Senior Notes | Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
5.375% Senior Notes | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	283,037	288,787
5.375% Senior Notes | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 0	$ 0
3.03% borrowings from FHLBI
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	3.03%	3.03%
Long-term debt, fair value	$ 57,638	$ 57,932
3.03% borrowings from FHLBI | Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
3.03% borrowings from FHLBI | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	57,638	57,932
3.03% borrowings from FHLBI | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 0	$ 0