Stock-based Compensation - Schedule of Stock Options Outstanding and Exercisable (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Options outstanding, beginning balance	567
Shares outstanding, Options exercised	(116)
Shares, Options outstanding, ending balance	451
Shares outstanding, Options vested and expected to vest, ending balance	450
Shares outstanding, Options exercisable, ending balance	417
Weighted average exercise price, Options outstanding, beginning balance | $ / shares	$ 13.67
Weighted average exercise price, Options exercised | $ / shares	(15.59)
Weighted average exercise price, Options outstanding, ending balance | $ / shares	13.18
Weighted average exercise price, Options vested and expected to vest, ending balance | $ / shares	13.18
Weighted average exercise price, Options exercisable, ending balance | $ / shares	$ 13.12
Weighted average remaining contractual term (years), Options outstanding	2 years 4 months 6 days
Weighted average remaining contractual term (years), Options vested and expected to vest	2 years 4 months 6 days
Weighted average remaining contractual term (years), Options exercisable	2 years 4 months 2 days
Aggregate intrinsic value, Options outstanding | $	$ 13,584
Aggregate intrinsic value, Options vested and expected to vest | $	13,549
Aggregate intrinsic value, Options exercisable | $	$ 12,578