Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Income Statement [Abstract]
Revenue	$ 247,865	$ 298,942
Cost of revenue	133,742	180,643
Gross profit	114,123	118,299
Operating expenses:
Research and development	89,336	87,758
Sales and marketing	72,052	91,174
General and administrative	36,088	30,746
Total operating expenses	197,476	209,678
Operating loss	(83,353)	(91,379)
Interest income, net	1,350	1,096
Other income, net	517	533
Loss before income taxes	(81,486)	(89,750)
Income tax benefit	(609)	(29,671)
Net loss	$ (80,877)	$ (60,079)
Net loss per share:
Basic (in dollars per share)	$ (0.34)	$ (0.27)
Diluted (in dollars per share)	$ (0.34)	$ (0.27)
Shares used to compute net loss per share:
Basic (in shares)	239,431	226,511
Diluted (in shares)	239,431	226,511