Fair Value Measurements - Summary of Fair Values of Assets and Liabilities Measured at Fair Value on Recurring and NonRecurring Basis (Details) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Cash and cash equivalents | $ 1,278 | $ 777 |
| Total assets | 1,278 | 777 |
| Warrants potentially settleable in cash | 548 | 569 |
| Total liabilities | 548 | 569 |
| Quoted Prices in Active Markets Level 1 [Member] | ||
| Cash and cash equivalents | 1,278 | 777 |
| Total assets | 1,278 | 777 |
| Warrants potentially settleable in cash | ||
| Total liabilities | ||
| Significant Other Observable Inputs Level 2 [Member] | ||
| Cash and cash equivalents | ||
| Total assets | ||
| Warrants potentially settleable in cash | ||
| Total liabilities | ||
| Unobservable Inputs Level 3 [Member] | ||
| Cash and cash equivalents | ||
| Total assets | ||
| Warrants potentially settleable in cash | 548 | 569 |
| Total liabilities | $ 548 | $ 569 |