Fair Value Measurement - Schedule of Reconciliation of the Beginning and Ending Level 3 Liabilities (Details) - USD ($) $ in Thousands  | 
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016  | 
Dec. 31, 2015  | 
Dec. 31, 2014  | 
|
| Estimated fair value of warrants assumed in merger on January 2, 2014 | $ 946 | ||
| Unobservable Inputs Level 3 [Member] | |||
| Balance - January 1 | 4,115 | 8,464 | 23 | 
| Value of warrants converted in cashless exercise | (36) | (14,265) | |
| Change in fair value of Teva option | (23) | ||
| Estimated fair value of warrants assumed in merger on January 2, 2014 | 10,475 | ||
| Estimated fair value of warrants issued in January common stock sale | 3,696 | ||
| Change in fair value of warrants for the year ended | (2,603) | 9,916 | (5,707) | 
| Balance at December 31 | $ 1,476 | $ 4,115 | $ 8,464 | 
| X | ||||||||||
- Definition Change in fair value of warrants for the year ended. No definition available. 
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| X | ||||||||||
- Definition Estimated fair value of warrants issued in January common stock sale. No definition available. 
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| X | ||||||||||
- Definition Value of warrants converted in cashless exercise. No definition available. 
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| X | ||||||||||
- Definition Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
- Definition Amount of expense (income) related to adjustment to fair value of warrant liability. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| 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 
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| X | ||||||||||
- Details 
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