Investments - Schedule of Credit Quality of Investment Securities With Contractual Maturities or The Issuer of Such Securities (Details) - USD ($) $ in Thousands |
Sep. 30, 2022 |
Dec. 31, 2021 |
|---|---|---|
| Debt Securities, Available-for-sale [Line Items] | ||
| Fair Value | $ 996,783 | $ 1,040,455 |
| % of Total Fair Value | 100.00% | 100.00% |
| AAA | ||
| Debt Securities, Available-for-sale [Line Items] | ||
| Fair Value | $ 297,030 | $ 321,975 |
| % of Total Fair Value | 29.80% | 31.00% |
| AA | ||
| Debt Securities, Available-for-sale [Line Items] | ||
| Fair Value | $ 150,936 | $ 139,186 |
| % of Total Fair Value | 15.20% | 13.40% |
| A | ||
| Debt Securities, Available-for-sale [Line Items] | ||
| Fair Value | $ 320,427 | $ 339,500 |
| % of Total Fair Value | 32.10% | 32.60% |
| BBB | ||
| Debt Securities, Available-for-sale [Line Items] | ||
| Fair Value | $ 225,154 | $ 234,358 |
| % of Total Fair Value | 22.60% | 22.50% |
| No Rating Available | ||
| Debt Securities, Available-for-sale [Line Items] | ||
| Fair Value | $ 3,236 | $ 5,436 |
| % of Total Fair Value | 0.30% | 0.50% |