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Description of Business and Basis of Presentation - Additional Information (Detail) $ in Thousands |  | 9 Months Ended |
--- | --- | --- | ---
Jul. 10, 2015 | Sep. 30, 2015 USD ($) | Sep. 30, 2014 USD ($) | Dec. 31, 2014 USD ($)
Description Of Business And Basis Of Presentation [Line Items] |  |  |  |
Forward stock split of its outstanding common stock | 1.8515 | 1.8515 |  |
Accumulated deficit |  | $ (172,723) |  | $ (12,741)
Net cash used in operating activities |  | $ (14,220) | $ (2,798) |
Common Stock |  |  |  |
Description Of Business And Basis Of Presentation [Line Items] |  |  |  |
Forward stock split of its outstanding common stock | 1.8515 |  |  |
Series B Preferred Stock |  |  |  |
Description Of Business And Basis Of Presentation [Line Items] |  |  |  |
Common stock, conversion basis |  | In March 2014, the Company entered into a definitive merger and share exchange agreement pursuant to which the Company redomesticated from the State of Illinois to the State of Delaware and the Illinois Company ceased to exist (the Redomestication). In connection with the Redomestication, the holders of Class A and Class B common stock received one share of Class A and Class B common stock of the Delaware Company, respectively, in exchange for fifteen shares of the Illinois Company. The holders of Series B preferred stock received one share of Series B preferred stock of the Delaware Company in exchange for one share of the Illinois Company. The holders of any options, warrants or other securities are subject to adjustment based on the ratio of one for fifteen. All share numbers and per share prices in the accompanying financial statements have been adjusted to reflect the 1 for 15 exchange. |  |
Forward stock split of its outstanding common stock |  | 0.067 |  |

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- Definition Describe the conversion features of common stock if such stock is convertible. That is, shares of common stock into which another convertible security was converted, or shares of common stock into which another class of common stock was converted. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
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- Definition Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585 + Details
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