Stockholders' Equity - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2019 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, beginning of period (in shares) | shares	16,263
Granted (in shares) | shares	0
Exercised (in shares) | shares	(479)
Canceled (in shares) | shares	(10)
Balance, end of period (in shares) | shares	15,774
Options exercisable (in shares) | shares	15,774
Options vested and expected to vest (in shares) | shares	15,181
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Balance, weighted average exercise price, beginning of period (in dollars per share)	$ 3.00
Granted, weighted average exercise price (in dollars per share)	0.00
Exercised, weighted average exercise price (in dollars per share)	1.99
Canceled, weighted average exercise price (in dollars per share)	3.03
Balance, weighted average exercise price, end of period (in dollars per share)	3.03
Options exercisable, weighted average exercise price (in dollars per share)	3.03
Options vested and expected to vest, weighted average exercise price (in dollars per share)	$ 2.88
Options outstanding, aggregate intrinsic value, end of period | $	$ 50,435
Options exercisable, aggregate intrinsic value | $	50,435
Options vested and expected to vest, aggregate intrinsic value | $	$ 50,010
Fair value of the Class A common stock (in dollars per share)	$ 5.92