Stock-Based Compensation Expense - Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding, Shares | shares	6,644
Granted | shares	1,930
Exercised | shares	(1,977)
Forfeited or expired | shares	(164)
Outstanding, Shares | shares	6,433
Exercisable, Shares | shares	2,037
Options vested or expected to vest | shares	5,837
Outstanding, Weighted-Average Exercise Price | $ / shares	$ 28.27
Granted, Weighted-Average Exercise Price | $ / shares	35.58
Exercised, Weighted-Average Exercise Price | $ / shares	21.99
Forfeited or expired, Weighted-Average Exercise Price | $ / shares	37.45
Outstanding, Weighted-Average Exercise Price | $ / shares	32.16
Exercisable, Weighted-Average Exercise Price | $ / shares	22.21
Options vested or expected to vest, Weighted-Average Exercise Price | $ / shares	$ 31.52
Outstanding, Weighted-Average Remaining Contractual Term (in years)	7 years 4 months 24 days
Exercisable, Weighted-Average Remaining Contractual Term (in years)	5 years 3 months 18 days
Options vested or expected to vest, Weighted-Average Remaining Contractual Term (in years)	7 years 2 months 12 days
Outstanding, Aggregate Intrinsic Value | $	$ 202,368
Exercisable, Aggregate Intrinsic Value | $	84,359
Options vested or expected to vest, Aggregate Intrinsic Value | $	$ 187,350