Income Taxes (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
Dec. 31, 2017 |
|
| Income Taxes | |||||
| Federal income tax at U.S. statutory rate | 21.00% | 35.00% | |||
| Provisional credit to federal tax expense | $ (2,400) | ||||
| Income tax benefit/(expense) | $ 6,311 | $ 1,328 | $ 9,868 | $ 4,194 | |
| Effective income tax rate ( as a percent) | 25.30% | 36.10% | 25.30% | 38.30% | |
| Valuation allowance, deferred tax assets | $ 0 | $ 0 | $ 0 | $ 0 | |