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Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands |  |  |  |  | 1 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 31, 2015 USD ($) shares | Jul. 10, 2015 | Jul. 08, 2015 USD ($) shares | Jun. 18, 2015 USD ($) $ / shares shares | Jun. 30, 2015 USD ($) shares | Apr. 30, 2015 USD ($) | Mar. 31, 2015 $ / shares shares | Dec. 31, 2014 USD ($) Director $ / shares shares | Apr. 30, 2014 USD ($) shares | Mar. 31, 2014 USD ($) | Sep. 30, 2015 USD ($) $ / shares shares | Dec. 31, 2010 USD ($) $ / shares shares | Jan. 01, 2015 USD ($)
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Forward stock split of its outstanding common stock |  | 1.8515 |  |  |  |  |  |  |  |  | 1.8515 |  |
Common stock, shares authorized |  |  |  |  | 100,000,000 |  |  |  |  |  |  |  |
Proceeds from issuance of common stock net of issuance costs | $ |  |  | $ 7,000 |  | $ 70,976 |  |  |  |  | $ 3,000 |  |  |
Common stock, shares issued | 9,531,200 |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sale of common stock | $ | $ 221,214 |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock | $ |  |  |  |  |  |  |  |  |  |  | $ 77,975 |  |
Promissory note agreed to convert |  |  |  |  |  |  |  |  | 114,369 |  |  |  |
Notes payable | $ |  |  |  |  |  |  |  |  | $ 1,000 |  |  |  |
Derivative Liability | $ |  |  |  |  |  |  |  |  |  |  |  |  | $ 177
Proceeds from exercise of warrants | $ |  |  |  |  |  |  |  |  |  |  | 7,340 |  |
Repurchase of common stock, value | $ |  |  |  |  |  |  |  |  |  |  | 4,798 |  |
Common Stock Warrant |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Liability | $ |  |  |  |  |  | $ 1,543 |  | $ 177 |  |  |  | $ 439 |
Private Placement |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock, Shares |  |  |  |  | 3,698,695 |  |  |  |  |  |  |  |
Issuance costs | $ |  |  |  |  | $ 28 |  |  |  |  |  |  |  |
Common stock, shares issued |  |  | 364,638 |  |  |  |  |  |  |  |  |  |
Issuance of common stock | $ |  |  |  |  |  |  |  |  |  |  | 17,000 |  |
Private Placement One |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of common stock net of issuance costs | $ | $ 17,000 |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares issued | 680,000 |  |  |  |  |  |  |  |  |  |  |  |
2013 Securities Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Notes payable | $ |  |  |  |  |  |  |  |  |  |  | $ 1,000 |  |
Minimum |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized | 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized | 500,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Common Class A |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Forward stock split of its outstanding common stock |  |  |  |  | 1.00 |  |  |  |  |  |  |  |
Common stock, shares authorized |  |  |  |  |  |  |  | 75,470,414 |  |  | 0 |  |
Common stock, shares issued |  |  |  |  |  |  |  | 61,094,367 |  |  | 0 |  |
Promissory note agreed to convert |  |  |  |  |  |  |  |  | 192,865 |  | 230,859 |  |
Conversion of Class A common stock to common stock, Shares |  |  |  |  |  |  |  |  |  |  | (65,900,303) |  |
Common stock issued for placement agent commission |  |  |  |  |  |  |  |  |  |  | 34,715 |  |
Stock price of warrants | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 2.44 |  |
Repurchase of common stock, shares |  |  |  | 249,952 |  |  |  |  |  |  | 249,952 |  |
Repurchase of common stock, par value | $ / shares |  |  |  | $ 19.20 |  |  |  |  |  |  |  |  |
Repurchase of common stock, value | $ |  |  |  | $ 4,798 |  |  |  |  |  |  |  |  |
Common Class A | Inex Bio Inc |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants issued to purchase common shares |  |  |  |  |  |  | 3,202,593 |  |  |  |  |  |
Stock price of warrants | $ / shares |  |  |  |  |  |  | $ 2.00 |  |  |  |  |  |
Proceeds from exercise of warrants | $ |  |  |  |  |  | $ 6,400 |  |  |  |  |  |  |
Common Class A | Common Stock Warrant |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants issued to purchase common shares |  |  |  |  |  |  |  |  |  |  |  | 114,822 |
Stock price of warrants | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 1.76 | $ 2.44 |
Warrant expiration date |  |  |  |  |  |  |  |  |  |  | Feb. 29, 2020 |  |
Warrant exercisable period |  |  |  |  |  |  |  |  |  |  | 2 years |  |
Percentage of shareholders consent |  |  |  |  |  |  |  |  |  |  | 66.67% |  |
Common Class A | Private Placement One | Sorrento |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock, Shares |  |  |  |  |  |  |  | 4,557,537 |  |  | 4,557,537 |  |
Common stock issued, par value | $ / shares |  |  |  |  |  |  |  | $ 1.76 |  |  |  |  |
Proceeds from issuance of common stock gross of issuance costs | $ |  |  |  |  |  |  |  | $ 8,000 |  |  | $ 8,000 |  |
Common Class A | Private Placement Two |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock, Shares |  |  |  |  |  |  |  | 26,252,262 |  |  |  |  |
Common stock issued, par value | $ / shares |  |  |  |  |  |  |  | $ 1.89 |  |  |  |  |
Proceeds from issuance of common stock gross of issuance costs | $ |  |  |  |  |  |  |  | $ 49,495 |  |  |  |  |
Number of board of directors | Director |  |  |  |  |  |  |  | 9 |  |  |  |  |
Common Class A | Private Placement Two | Sorrento |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock, Shares |  |  |  |  |  |  |  | 1,060,789 |  |  | 1,060,789 |  |
Issuance costs | $ |  |  |  |  |  |  |  | $ 159 |  |  |  |  |
Issuance of common stock | $ |  |  |  |  |  |  |  | $ 2,000 |  |  | $ 2,000 |  |
Common Class A | 2013 Securities Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Promissory note agreed to convert |  |  |  |  |  |  |  |  |  |  | 389,437 |  |
Notes payable | $ |  |  |  |  |  |  |  |  |  |  | $ 950 |  |
Conversion of Class A common stock to common stock, Shares |  |  |  |  |  |  |  |  |  |  | 406,048 |  |
Common Class A | 2014 Securities Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Commissions | $ |  |  |  |  |  |  |  |  |  |  | $ 45 |  |
Common stock issued for placement agent commission |  |  |  |  |  |  |  |  |  |  | 34,715 |  |
Common Stock Class Undefined |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized |  |  |  |  |  |  |  | 80,000,000 |  |  | 500,000,000 |  |
Issuance of common stock, Shares |  |  |  |  |  |  |  |  |  |  | 4,063,333 |  |
Common stock, shares issued |  |  |  |  |  |  |  | 0 |  |  | 81,212,662 |  |
Conversion of Class A common stock to common stock, Shares |  |  |  |  |  |  |  |  |  |  | 65,900,303 |  |
Common Stock Class Undefined | Private Placement |  |  |  |  |  |  |  |  |  |  |  |  |
Class Of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock, Shares |  |  |  |  |  |  |  |  |  |  | 680,000 |  |

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