Stockholders' Equity - Summary of Warrant Activity (Detail) - Warrants [Member] $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding at beginning of period, Number of Shares | shares	84,986
Warrants granted, Number of Shares | shares	1,701,583
Warrants exercised, Number of Shares | shares	0
Warrants forfeitures, Number of Shares | shares	0
Warrants outstanding at end of period, Number of Shares | shares	1,786,569
Warrants outstanding at beginning of period, Weighted Average Exercise Price Per Share | $ / shares	$ 3.53
Warrants granted, Weighted Average Exercise Price Per Share | $ / shares	2.38
Warrants exercised, Weighted Average Exercise Price Per Share | $ / shares	0
Warrants forfeitures, Weighted Average Exercise Price Per Share | $ / shares	0
Warrants outstanding at end of period, Weighted Average Exercise Price Per Share | $ / shares	$ 2.43
Warrants outstanding, Aggregate Intrinsic Value | $	$ 970