Stock-Based Compensation Expense - Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jul. 01, 2018 USD ($) $ / shares shares
Shares (in thousands)
Outstanding, shares | shares	12,726
Granted, shares | shares	2,119
Exercised, shares | shares	(881)
Forfeited or expired, shares | shares	(373)
Outstanding, shares | shares	13,591
Exercisable as of reporting date, shares | shares	4,781
Options vested or expected to vest as of reporting date, shares | shares	12,177
Weighted- Average Exercise Price
Outstanding, shares | $ / shares	$ 25.24
Granted, in dollars per share | $ / shares	56.03
Exercised, in dollars per share | $ / shares	16.82
Forfeited or expired, in dollars per share | $ / shares	32.68
Outstanding, shares | $ / shares	30.39
Exercisable as of reporting date, Weighted-Average Exercise Price, in dollars per share | $ / shares	19.98
Weighted- Average Remaining Contractual Term (in years) | $ / shares	$ 29.20
Weighted- Average Remaining Contractual Term (in years)
Outstanding, in years	7 years 7 months 13 days
Exercisable, in years	6 years 2 months 1 day
Options vested or expected to vest, in years	7 years 5 months 27 days
Aggregate Intrinsic Value (in thousands)
Outstanding, in dollars | $	$ 223,515
Exercisable, in dollars | $	117,767
Options vested or expected to vest, in dollars | $	$ 210,965