Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Compensation Related Costs [Abstract]
Shares, Options outstanding as of December 31, 2015		10,322,903
Shares, Granted		847,450
Shares, Exercised		(2,129,090)
Shares, Expired and forfeited		(185,055)
Shares, Options outstanding as of December 31, 2016		8,856,208	10,322,903
Shares, Options expected to vest at December 31, 2016		1,753,013
Shares, Exercisable at December 31, 2016		7,103,016
Weighted Average Exercise Price, Outstanding as of December 31, 2015		$ 44.50
Weighted Average Exercise Price, Granted		84.31
Weighted Average Exercise Price, Exercised		29.23
Weighted Average Exercise Price, Expired and forfeited		84.78
Weighted Average Exercise Price, Outstanding as of December 31, 2016		51.13	$ 44.50
Weighted Average Exercise Price, Expected to Vest at December 31, 2016		84.38
Weighted Average Exercise Price, Exercisable at December 31, 2016		$ 42.92
Weighted Average Remaining Years, Options outstanding		5 years 4 months 24 days	5 years 7 months 6 days
Options expected to vest at December 31, 2016		8 years 3 months 18 days
Weighted Average Remaining Years, Exercisable at December 31, 2016		4 years 7 months 6 days
Aggregate Intrinsic Value, Options outstanding	[1]	$ 630,949
Aggregate Intrinsic Value, Options outstanding	[1]	304,356	$ 630,949
Aggregate Intrinsic Value, Options expected to vest at December 31, 2016	[1]	10,707
Aggregate Intrinsic Value, Exercisable at December 31, 2016	[1]	$ 293,646

[1] The aggregate intrinsic value for outstanding options is calculated as the difference between the exercise price of the underlying awards and the quoted price of the Company’s common stock as of the last trading day for the respective year. The aggregate intrinsic value of options outstanding and exercisable includes options with an exercise price below $82.84, the closing price of the Company’s common stock on December 31, 2016.