Stock-Based Compensation - Summary of Stock Options Outstanding (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options, Options outstanding, Beginning Balance	7,108
Number of Options, Options granted	19
Number of Options, Options exercised	(283)	(60)	(147)
Number of Options, Options forfeited	(93)
Number of Options, Options expired	(413)
Number of Options, Options outstanding, Ending Balance	6,338	7,108
Number of Options, Options vested and expected to vest	6,276
Number of Options, Options exercisable	4,757
Weighted Average Exercise Price, Options outstanding, Beginning Balance	$ 21.97
Weighted Average Exercise Price, Options granted	18.24
Weighted Average Exercise Price, Options exercised	16.66
Weighted Average Exercise Price, Options forfeited	17.90
Weighted Average Exercise Price, Options expired	23.96
Weighted Average Exercise Price, Options outstanding, Ending Balance	22.14	$ 21.97
Weighted Average Exercise Price, Options vested and expected to vest	22.20
Weighted Average Exercise Price, Options exercisable	$ 23.67
Weighted Average Remaining Contractual Life In Years, Options outstanding	5 years 7 months 17 days	6 years 5 months 1 day
Weighted Average Remaining Contractual Life In Years, Options vested and expected to vest	5 years 7 months 6 days
Weighted Average Remaining Contractual Life In Years, Options exercisable	4 years 8 months 23 days
Aggregate Intrinsic Value, Options outstanding, Beginning Balance	$ 3,284
Aggregate Intrinsic Value, Options outstanding, Ending Balance	16,972	$ 3,284
Aggregate Intrinsic Value, Options vested and expected to vest	16,606
Aggregate Intrinsic Value, Options exercisable	$ 9,137