| Common Stock Warrants - Additional Information (Details) | 3 Months Ended | 
|---|---|
| Mar. 31, 2017  $ / shares  shares | |
| Class Of Warrant Or Right [Line Items] | |
| Warrants expiration period | 2017-03 | 
| Five Year Warrants Issued in March 2012 [Member] | |
| Class Of Warrant Or Right [Line Items] | |
| Aggregate number of unregistered shares of common stock called by warrants (in shares) | shares | 741,729 | 
| Exercise price of warrants (in dollars per share) | $ / shares | $ 35.20 | 
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- Definition Exercise price per share or per unit of warrants or rights outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The month and year (YYYY-MM) in which the warrants or rights expire. No definition available. 
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- Details 
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