v3.26.3
Fair Value Measurements - Schedule of Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fixed income securities, held-to-maturity, fair value $ 20,984 $ 23,939
Commercial mortgage loans, fair value 279,076 274,895
Long-term debt, fair value 854,835 924,252
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
Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fixed income securities, held-to-maturity, fair value 20,984 23,939
Commercial mortgage loans, fair value 0 0
Long-term debt, fair value 854,835 924,252
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 279,076 274,895
Long-term debt, fair value 0 0
3.03% borrowings from FHLBI    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value $ 59,816 $ 59,625
Interest rate (as a percent) 3.03% 3.03%
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 59,816 59,625
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
Senior Notes | 7.25% Senior Notes    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value $ 52,934 $ 56,973
Interest rate (as a percent) 7.25% 7.25%
Senior Notes | 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
Senior Notes | 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 52,934 56,973
Senior Notes | 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
Senior Notes | 6.70% Senior Notes    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value $ 101,158 $ 110,244
Interest rate (as a percent) 6.70% 6.70%
Senior Notes | 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
Senior Notes | 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 101,158 110,244
Senior Notes | 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
Senior Notes | 5.90% Senior Notes    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value $ 389,612 $ 419,869
Interest rate (as a percent) 5.90% 5.90%
Senior Notes | 5.90% 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
Senior Notes | 5.90% Senior Notes | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value 389,612 419,869
Senior Notes | 5.90% Senior Notes | Significant Unobservable Inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value 0 0
Senior Notes | 5.375% Senior Notes    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value $ 251,315 $ 277,541
Interest rate (as a percent) 5.375% 5.375%
Senior Notes | 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
Senior Notes | 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 251,315 277,541
Senior Notes | 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
Corporate securities    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fixed income securities, held-to-maturity, fair value 20,984 23,939
Corporate securities | 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
Corporate securities | Significant Other Observable Inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fixed income securities, held-to-maturity, fair value 20,984 23,939
Corporate securities | 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