CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2018 |
Dec. 31, 2017 |
|
| Statement of Stockholders' Equity [Abstract] | ||
| Change in unrealized investment gains/losses, tax (benefit) expense | $ (3,314) | $ 1,307 |
| Stock issued upon exercise of warrants (in shares) | 29,437 | 32,368 |
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |