Stock-Based Compensation - Stock Option Activity (Detail)	3 Months Ended
	Mar. 31, 2016 $ / shares shares
Share Based Compensation [Abstract]
Option activity, Outstanding, Beginning balance | shares	2,607,417
Option activity shares, Granted | shares	45,000
Option activity, Exercised | shares	(56,250)
Option activity, Forfeited | shares	(912)
Option activity outstanding, Ending balance | shares	2,595,255
Option activity, Exercisable, Ending balance | shares	2,009,730
Option activity, Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 7.41
Option activity Weighted Average Exercise Price, Granted	4.21
Option activity Weighted Average Exercise Price, Exercised	4.20
Option activity Weighted Average Exercise Price, Forfeited	4.95
Option activity, Weighted Average Exercise Price, Outstanding, Ending Balance	7.42
Option activity Weighted Average Exercise Price, Exercisable, Ending Balance	$ 7.96
Option activity Weighted Average Remaining Contractual Life (Years)	5 years 10 months 24 days
Option activity Weighted Average Fair Value of Option Grants	$ 2.05