v3.25.2
Fair Value of Financial Instruments - Carrying Values and Estimated Fair Values of Financial Instruments (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Available-for-sale debt securities, at fair value $ 3,096,708 $ 2,946,126  
Fixed-maturity security held to maturity, fair value 1,225,532 1,227,428  
Equity securities 24,867 27,144  
Separate account assets 2,318,492 2,209,287  
Surplus note 1,258,508 1,303,556  
Separate account liabilities 2,318,492 2,209,287 $ 2,395,842
Fixed-maturity security (held-to-maturity) 1,258,800 1,303,880  
Reported Value Measurement [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Available-for-sale debt securities, at fair value 3,096,708 2,946,126  
Equity securities 24,867 27,144  
Trading securities 2,969 3,011  
Separate account assets 2,318,492 2,209,287  
Separate account liabilities 2,318,492 2,209,287  
Reported Value Measurement [Member] | Level 3 [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Policy loans [1] 43,727 40,884  
Surplus note [1],[2] 1,258,508 1,303,556  
Fixed-maturity security (held-to-maturity) [1] 1,258,800 1,303,880  
Reported Value Measurement [Member] | Level 3 [Member] | Deposits [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Deposit asset underlying 10% coinsurance agreement [1] 146,266 158,913  
Reported Value Measurement [Member] | Level 2 [Member] | Senior Notes [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Note payable - Long term [2],[3] 594,913 594,512  
Estimate of Fair Value Measurement [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Available-for-sale debt securities, at fair value 3,096,708 2,946,126  
Equity securities 24,867 27,144  
Trading securities 2,969 3,011  
Separate account assets 2,318,492 2,209,287  
Separate account liabilities 2,318,492 2,209,287  
Estimate of Fair Value Measurement [Member] | Level 3 [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Fixed-maturity security held to maturity, fair value [1] 1,225,532 1,227,428  
Policy loans [1] 43,727 40,884  
Surplus note [1],[2] 1,222,148 1,225,708  
Estimate of Fair Value Measurement [Member] | Level 3 [Member] | Deposits [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Deposit asset underlying 10% coinsurance agreement [1] 146,266 158,913  
Estimate of Fair Value Measurement [Member] | Level 2 [Member] | Senior Notes [Member]      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Note payable - Long term [2],[3] $ 530,488 $ 513,862  
[1] Classified as a Level 3 fair value measurement.
[2] Carrying value amounts shown are net of unamortized issuance costs.
[3] Classified as a Level 2 fair value measurement.