Stock-Based Compensation - Summary of Stock Options Outstanding and Exercisable (Detail) - 2012 and 2014 Plan Excluding Conditional and Inducement Grants [Member] | 3 Months Ended |
Mar. 31, 2017$ / sharesshares |
$0.57 - $0.57 [Member] | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
Options Outstanding, Exercise Price, Minimum | $ 0.57 |
Options Outstanding, Exercise Price, Maximum | $ 0.57 |
Options Outstanding, Number of Shares | shares | 90,000 |
Options Outstanding, Weighted Average Remaining Contractual Life (in years) | 9 years 7 months 2 days |
Options Outstanding, Weighted Average Exercise Price | $ 0.57 |
Options Exercisable, Number of Shares | shares | 29,998 |
Options Exercisable,Weighted Average Exercise Price | $ 0.57 |
$0.85 - $0.85 [Member] | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
Options Outstanding, Exercise Price, Minimum | 0.85 |
Options Outstanding, Exercise Price, Maximum | $ 0.85 |
Options Outstanding, Number of Shares | shares | 400,000 |
Options Outstanding, Weighted Average Remaining Contractual Life (in years) | 9 years 8 months 23 days |
Options Outstanding, Weighted Average Exercise Price | $ 0.85 |
Options Exercisable, Number of Shares | shares | 0 |
Options Exercisable,Weighted Average Exercise Price | $ 0 |
$1.14 - $2.11 [Member] | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
Options Outstanding, Exercise Price, Minimum | 1.14 |
Options Outstanding, Exercise Price, Maximum | $ 2.11 |
Options Outstanding, Number of Shares | shares | 180,780 |
Options Outstanding, Weighted Average Remaining Contractual Life (in years) | 6 years 11 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $ 1.36 |
Options Exercisable, Number of Shares | shares | 133,922 |
Options Exercisable,Weighted Average Exercise Price | $ 1.39 |
$2.26 - $2.26 [Member] | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
Options Outstanding, Exercise Price, Minimum | 2.26 |
Options Outstanding, Exercise Price, Maximum | $ 2.26 |
Options Outstanding, Number of Shares | shares | 328,394 |
Options Outstanding, Weighted Average Remaining Contractual Life (in years) | 8 years 8 months 16 days |
Options Outstanding, Weighted Average Exercise Price | $ 2.26 |
Options Exercisable, Number of Shares | shares | 103,869 |
Options Exercisable,Weighted Average Exercise Price | $ 2.26 |
$2.34 - $9.29 [Member] | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
Options Outstanding, Exercise Price, Minimum | 2.34 |
Options Outstanding, Exercise Price, Maximum | $ 9.29 |
Options Outstanding, Number of Shares | shares | 499,826 |
Options Outstanding, Weighted Average Remaining Contractual Life (in years) | 8 years 9 months 11 days |
Options Outstanding, Weighted Average Exercise Price | $ 3.06 |
Options Exercisable, Number of Shares | shares | 235,825 |
Options Exercisable,Weighted Average Exercise Price | $ 3.14 |