Stock-Based Compensation - Summary of Stock Options Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options, Options outstanding, Beginning Balance	6,338,000
Number of Options, Options granted	0	0
Number of Options, Options exercised	(82,000)
Number of Options, Options forfeited	(12,000)
Number of Options, Options expired	(16,000)
Number of Options, Options outstanding, Ending Balance	6,228,000		6,338,000
Number of Options, Options vested and expected to vest	6,228,000
Number of Options, Options exercisable	4,660,000
Weighted Avg. Exercise Price, Options outstanding, Beginning Balance	$ 22.14
Weighted Avg. Exercise Price, Options exercised	16.84
Weighted Avg. Exercise Price, Options forfeited	17.84
Weighted Avg. Exercise Price, Options expired	26.18
Weighted Avg. Exercise Price, Options outstanding, Ending Balance	22.21		$ 22.14
Weighted Avg. Exercise Price, Options vested and expected to vest	22.21
Weighted Avg. Exercise Price, Options exercisable	$ 23.78
Weighted Avg. Remaining Contractual Life In Years, Options outstanding	5 years 4 months 17 days		5 years 7 months 17 days
Weighted Avg. Remaining Contractual Life In Years, Options vested and expected to vest	5 years 4 months 17 days
Weighted Avg. Remaining Contractual Life In Years, Options exercisable	4 years 5 months 19 days
Aggregate Intrinsic Value, Options outstanding	$ 11,692		$ 16,972
Aggregate Intrinsic Value, Options vested and expected to vest	11,692
Aggregate Intrinsic Value, Options exercisable	$ 6,111