Stock-Based Compensation - Option Activity (Detail) - Stock Option [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares
Outstanding, Beginning Balance	1,316	1,828	3,287
Options granted	31	31	120
Options exercised	(155)	(365)	(612)
Options canceled/forfeited	(107)	(178)	(967)
Outstanding, Ending Balance	1,085	1,316	1,828
Options exercisable	422
Options vested and expected to vest	1,085
Shares available for future grant	2,345
Weighted Average Exercise Price
Outstanding, Beginning Balance	$ 12.81	$ 12.51	$ 10.72
Options granted	17.26	19.38	15.61
Options exercised	13.12	11.48	8.44
Options canceled/forfeited	13.06	13.58	9.38
Outstanding, Ending Balance	12.86	$ 12.81	$ 12.51
Options exercisable	12.14
Options vested and expected to vest	$ 12.86
Weighted Average Remaining Contractual Life
Outstanding, contractual life (in years)	3 years 9 months 11 days
Options exercisable (in years)	2 years 4 months 17 days
Options vested and expected to vest (in years)	3 years 9 months 11 days
Aggregate Intrinsic Value
Outstanding intrinsic value	$ 2,819
Options exercisable	1,351
Options vested and expected to vest	$ 2,819