Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Income Statement [Abstract]
Revenue	$ 299,344	$ 353,299	$ 547,209	$ 652,241
Cost of revenue	180,329	204,054	314,071	384,697
Gross profit	119,015	149,245	233,138	267,544
Operating expenses:
Research and development	87,047	80,543	176,383	168,301
Sales and marketing	100,845	100,732	172,897	191,906
General and administrative	30,211	31,379	66,299	62,125
Total operating expenses	218,103	212,654	415,579	422,332
Operating loss	(99,088)	(63,409)	(182,441)	(154,788)
Interest income, net	2,177	193	3,527	1,289
Other income, net	2,258	303	2,775	836
Loss before income taxes	(94,653)	(62,913)	(176,139)	(152,663)
Income tax expense (benefit)	23,615	(4,673)	23,006	(34,344)
Net loss	$ (118,268)	$ (58,240)	$ (199,145)	$ (118,319)
Net loss per share:
Basic (in dollars per share)	$ (0.49)	$ (0.25)	$ (0.83)	$ (0.52)
Diluted (in dollars per share)	$ (0.49)	$ (0.25)	$ (0.83)	$ (0.52)
Shares used to compute net loss per share:
Basic (in shares)	242,898	230,322	241,227	228,788
Diluted (in shares)	242,898	230,322	241,227	228,788