Investments - Net Investment Income (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | $ 57,641 | $ 56,183 | $ 116,076 | $ 111,910 | ||
| Investment expenses | (2,092) | (2,072) | (4,188) | (4,208) | ||
| Investment income net of investment expenses | 55,549 | 54,111 | 111,888 | 107,702 | ||
| Interest expense on surplus note | (14,621) | (15,659) | (29,289) | (31,444) | ||
| Net investment income | 40,928 | 38,452 | 82,599 | 76,258 | ||
| Equity Securities [Member] | ||||||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | 315 | 323 | 630 | 712 | ||
| Policy Loans and Other Invested Assets [Member] | ||||||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | 482 | 543 | 1,514 | 1,005 | ||
| Cash, Cash Equivalents and Short-Term Investments [Member] | ||||||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | 5,959 | 6,640 | 12,478 | 13,621 | ||
| Total return on deposit asset underlying 10% insurance agreement [Member] | ||||||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | [1] | 1,918 | 2,400 | 4,306 | 4,574 | |
| Available-for-Sale [Member] | Fixed Maturities | ||||||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | 34,346 | 30,618 | 67,859 | 60,554 | ||
| Held-to-Maturity [Member] | Fixed Maturities | ||||||
| Net Investment Income [Line Items] | ||||||
| Gross investment income, operating | $ 14,621 | $ 15,659 | $ 29,289 | $ 31,444 | ||
| ||||||