Nature of Business and Basis of Presentation - Comprehensive Income (Details) - USD ($) $ in Thousands |
Dec. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ||
| Total accumulated comprehensive loss | $ (595) | $ (247) |
| Accumulated Net Investment Gain (Loss) Attributable to Parent | ||
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ||
| Other comprehensive income (loss) before tax | (825) | (348) |
| Deferred tax benefit (expense) | 227 | 97 |
| Total accumulated comprehensive loss | (598) | (251) |
| Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent | ||
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ||
| Other comprehensive income (loss) before tax | 5 | 6 |
| Deferred tax benefit (expense) | (2) | (2) |
| Total accumulated comprehensive loss | 3 | 4 |
| Accumulated Other Comprehensive Loss | ||
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ||
| Total accumulated comprehensive loss | $ (595) | $ (247) |