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Stockholders' Equity (Deficit) - Additional Information (Detail) (USD $) | 12 Months Ended |  |  |  | 0 Months Ended | 24 Months Ended | 0 Months Ended | 12 Months Ended | 0 Months Ended | 12 Months Ended | 0 Months Ended | 1 Months Ended | 12 Months Ended | 0 Months Ended | 12 Months Ended |
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Dec. 31, 2013 | Dec. 31, 2011 | Dec. 31, 2012 | May 16, 2006 | Oct. 12, 2004 | Oct. 16, 2013 IPO [Member] | Jan. 11, 2011 Series D-2 Convertible Preferred Stock [Member] | Dec. 31, 2003 Series A Preferred Stock [Member] | Oct. 12, 2004 Series B Preferred Stock [Member] | Dec. 31, 2013 Series B Preferred Stock [Member] | May 16, 2006 Series C Preferred Stock [Member] | Dec. 31, 2013 Series C Preferred Stock [Member] | Dec. 31, 2013 Series D Preferred Stock [Member] | Jul. 16, 2008 Series D Preferred Stock [Member] Raven Biotechnologies Inc [Member] | Mar. 31, 2011 Series D Preferred Stock [Member] Raven Biotechnologies Inc [Member] | Dec. 31, 2013 Series A- One Preferred Stock [Member] | Dec. 31, 2013 Series A- Two Preferred Stock [Member] | May 16, 2010 Series D Two Preferred Stock [Member] | Sep. 19, 2008 Series D Two Preferred Stock [Member] | Dec. 31, 2013 Series D Two Preferred Stock [Member] | Dec. 31, 2013 Undesignated Preferred Stock [Member]
Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued or sold |  |  |  |  |  | 5,000,000 | 18,427,388 | 34,239,374 | 71,401,237 |  | 110,952,217 |  |  |  |  |  |  | 6,916,110 | 38,337,678 |  |
Proceeds from issuance of convertible preferred stock |  | $ 12,014,816 |  |  |  |  |  | $ 34,000,000 | $ 30,300,000 |  | $ 44,900,000 |  |  |  |  |  |  |  | $ 24,800,000 |  |
Price per share |  |  |  |  |  | $ 16.00 |  | $ 1.00 |  |  |  |  |  |  |  |  |  |  |  |  |
Related offering costs |  |  |  |  |  |  |  |  | 238,000 |  | 101,246 |  |  |  |  |  |  |  | 156,788 |  |
Shares of common stock allocated |  |  |  | 10,003,300 | 13,604,016 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued to acquire entity |  |  |  |  |  |  |  |  |  |  |  |  |  | 12,466,039 | 14,446,227 |  |  |  |  |  |
Purchased shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 518,708 | 2,875,327 |  |
Exercise price |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.65 |
Proceeds from sale of shares |  |  |  |  |  |  | 12,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Accrued noncumulative dividends on preferred stock |  |  |  |  |  |  |  |  |  | $ 0.0341 |  | $ 0.0324 | $ 0.0522 |  |  | $ 0.08 | $ 0.08 |  |  | $ 0.0522 |
Convertible preferred stock series |  |  |  |  |  |  |  |  |  | 1.14 |  | 1.00 | 1.00 |  |  | 1.506 | 1.00 |  |  | 1.00 |
Conversion price of preferred stock |  |  |  |  |  |  |  |  |  | $ 6.95 |  | $ 7.70 | $ 12.20 |  |  | $ 12.39 | $ 18.77 |  |  | $ 12.20 |
Additional shares sold under over-allotments Option to underwriter |  |  |  |  |  | 750,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from initial public offering net of expenses |  |  |  |  |  | $ 83,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reverse stock split | 1-for-18.7739 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized | 125,000,000 |  | 425,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Undesignated preferred stock, shares authorized |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,000,000
Undesignated preferred stock, par value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.01
Undesignated preferred stock, shares issued |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0
Undesignated preferred stock, shares outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0

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