CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands |
Jun. 30, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Fixed maturities, available-for-sale, amortized cost | $ 852,029 | $ 713,859 |
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Common stock, issued (in shares) | 65,753,784 | 60,517,512 |
| Common stock, outstanding (in shares) | 65,753,784 | 60,517,512 |
| Common stock, authorized (in shares) | 250,000,000 | 250,000,000 |