Stock-Based Compensation - Option Activity (Detail) - Stock Option [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares
Outstanding, Beginning Balance	1,085	1,316	1,828
Options granted	27	31	31
Options exercised	(170)	(155)	(365)
Options canceled/forfeited	(264)	(107)	(178)
Outstanding, Ending Balance	678	1,085	1,316
Options exercisable	279
Options vested and expected to vest	678
Shares available for future grant	2,077
Weighted Average Exercise Price
Outstanding, Beginning Balance	$ 12.86	$ 12.81	$ 12.51
Options granted	13.03	17.26	19.38
Options exercised	7.56	13.12	11.48
Options canceled/forfeited	11.06	13.06	13.58
Outstanding, Ending Balance	14.90	$ 12.86	$ 12.81
Options exercisable	15.37
Options vested and expected to vest	$ 14.90
Weighted Average Remaining Contractual Life
Outstanding, contractual life (in years)	4 years 4 months 13 days
Options exercisable (in years)	3 years 4 days
Options vested and expected to vest (in years)	4 years 4 months 13 days
Aggregate Intrinsic Value
Outstanding intrinsic value	$ 314
Options exercisable	122
Options vested and expected to vest	$ 314