Investments - Net Investment Income (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Schedule of Investments [Line Items] | ||||
| Investment income | $ 31,849 | $ 35,333 | $ 64,703 | $ 69,316 |
| Investment expenses | (727) | (1,073) | (1,559) | (2,187) |
| Net investment income | 31,122 | 34,260 | 63,144 | 67,129 |
| Fixed maturities | ||||
| Schedule of Investments [Line Items] | ||||
| Investment income | 23,522 | 32,914 | 49,742 | 65,042 |
| Funds withheld interest | ||||
| Schedule of Investments [Line Items] | ||||
| Investment income | 5,169 | 54 | 9,706 | 113 |
| Loan to related party | ||||
| Schedule of Investments [Line Items] | ||||
| Investment income | 1,842 | 1,565 | 3,664 | 2,993 |
| Cash and cash equivalents and other | ||||
| Schedule of Investments [Line Items] | ||||
| Investment income | $ 1,316 | $ 800 | $ 1,591 | $ 1,168 |