Stock-Based Compensation - Schedule of Stock Option Plans Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding at beginning of year, Shares | shares	3,591
Granted, Shares | shares	698
Exercised, Shares | shares	(144)
Canceled, Shares | shares	0
Outstanding at end of year, Shares | shares	4,145
Stock Options exercisable at end of year, Shares | shares	1,848
Outstanding at beginning of year, Weighted - Average Exercise Price | $ / shares	$ 45.32
Granted, Weighted - Average Exercise Price | $ / shares	59.07
Exercised, Weighted - Average Exercise Price | $ / shares	37.54
Canceled, Weighted - Average Exercise Price | $ / shares	0
Outstanding at end of period, Weighted - Average Exercise Price | $ / shares	47.90
Stock options exercisable at end of year, Weighted - Average Exercise Price | $ / shares	$ 43.37
Outstanding at end of period, Weighted - Average Remaining Contractual Life	7 years 4 days
Stock options exercisable at end of period, Weighted - Average Remaining Contractual Life	5 years 2 months 12 days
Exercised, Aggregate Intrinsic Value | $	$ 3,618
Outstanding at end of period, Aggregate Intrinsic Value | $	35,842
Stock options exercisable at end of period, Aggregate Intrinsic Value | $	$ 23,415