Stockholders' Equity - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding at beginning of period | shares	3,397,529
Number of Shares, Exercised | shares	(147,425)
Number of Shares, Forfeitures | shares	(394,898)
Number of Shares, Outstanding at end of period | shares	3,336,509
Weighted Average Exercise Price Per Share, Outstanding at beginning of period | $ / shares	$ 5.42
Weighted average Exercise Price Per Share, Exercised | $ / shares	2.01
Weighted Average Exercise Price Per Share, Forfeitures | $ / shares	9.06
Weighted Average Exercise Price Per Share, Outstanding at end of period | $ / shares	$ 4.83
Aggregate Intrinsic Value, Outstanding at end of period | $	$ 459
Officers and Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted in 2016 | shares	95,000
Weighted Average Exercise Price Per Share, Granted in 2016 | $ / shares	$ 2.34
Others [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted in 2016 | shares	386,303
Weighted Average Exercise Price Per Share, Granted in 2016 | $ / shares	$ 3.49