Fair Value Measurement - Schedule of Reconciliation of Beginning and Ending Level 3 Liabilities (Details) - Unobservable Inputs Level 3 [Member] - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Balance - January 1 | $ 1,476 | $ 4,115 | $ 8,464 |
| Value of warrants converted in cashless exercise | (36) | (14,265) | |
| Change in fair value of warrants | (907) | (2,603) | 9,916 |
| Balance at December 31 | $ 569 | $ 1,476 | $ 4,115 |
| X | ||||||||||
- Definition Change in fair value of warrants for the year ended. No definition available.
|
| X | ||||||||||
- Definition Value of warrants converted in cashless exercise. No definition available.
|
| X | ||||||||||
- Definition Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|