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Warrants - Additional Information (Detail) - USD ($) |  |  |  |  |  | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 21, 2015 | Dec. 03, 2014 | Jul. 20, 2012 | Sep. 30, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2016 | Mar. 31, 2015
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |
Warrant expense |  |  |  |  |  |  | $ 3,100,000 | $ 11,000 |  |
Investor Warrants [Member] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrants or right to purchase common stock |  |  |  |  |  |  |  |  | 13,333,334 |
Class of Warrants or right to purchase common stock, exercise price |  |  |  |  |  |  |  |  | $ 2.25 |
Warrants exercisable period |  |  |  |  |  |  | 6 months |  |  |
Warrants expiry period |  |  |  |  |  |  | 5 years |  |  |
Warrant expense | $ 2.28 |  |  |  |  |  | $ 2.28 |  |  |
Placement Agent Warrant [Member] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrants or right to purchase common stock |  |  |  |  |  |  |  |  | 133,333 |
Class of Warrants or right to purchase common stock, exercise price |  |  |  |  |  |  |  |  | $ 2.25 |
Warrants expiry period |  |  |  |  |  |  | 5 years |  |  |
Warrant expense |  |  |  |  |  |  | $ 2.28 |  |  |
Consulting Agreement Warrant [Member] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrants or right to purchase common stock |  |  |  |  |  |  |  |  |  | 7,398
Class of Warrants or right to purchase common stock, exercise price |  |  |  |  |  |  |  |  |  | $ 9.75
Warrants exercisable period |  |  |  |  |  | 24 months |  |  |  |
Warrants expiry period |  |  |  |  |  | 10 years |  |  |  |
Warrants, forfeiture |  |  | (3,699) |  |  |  |  |  |  |
Warrants vested and exercisable | 3,699 | 3,699 |  |  |  |  |  |  |  |
Warrants, percentage of forfeiture |  |  | 50.00% |  |  |  |  |  |  |
Affiliates Of Advisor Warrant [Member] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrants or right to purchase common stock | 156,138 | 156,138 |  |  | 161,977 |  | 156,138 | 156,138 |  |
Class of Warrants or right to purchase common stock, exercise price | $ 0.01 | $ 0.01 |  |  | $ 0.01 |  | $ 0.01 | $ 0.01 |  |
Warrants expiry period |  |  |  |  | 10 years |  |  |  |  |
Fair value of the warrants, risk-free interest rate |  |  |  |  | 0.22% |  |  |  |  |
Fair value of the warrants, implied volatility |  |  |  |  | 99.00% |  |  |  |  |
Fair value of the warrants, expected term to liquidity even |  |  |  |  | 1 year 8 months 12 days |  |  |  |  |
Surrender of warrant to satisfy related liability |  |  |  | 5,839 |  |  |  |  |  |

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- Definition Adjustment for noncash service expenses paid for by granting of warrants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
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- Definition Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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