Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 393,575	$ 392,522	$ 940,784	$ 1,044,763
Cost of revenue	240,061	217,762	554,132	602,459
Gross profit	153,514	174,760	386,652	442,304
Operating expenses:
Research and development	79,840	84,170	256,223	252,471
Sales and marketing	66,676	77,536	239,573	269,442
General and administrative	24,812	40,690	91,111	102,815
Total operating expenses	171,328	202,396	586,907	624,728
Operating loss	(17,814)	(27,636)	(200,255)	(182,424)
Interest income, net	2,072	1,162	5,599	2,451
Other income (expense), net	(5,141)	(702)	(2,366)	134
Loss before income taxes	(20,883)	(27,176)	(197,022)	(179,839)
Income tax expense (benefit)	(18,827)	86,227	4,179	51,883
Net loss	$ (2,056)	$ (113,403)	$ (201,201)	$ (231,722)
Net loss per share:
Basic (in dollars per share)	$ (0.01)	$ (0.48)	$ (0.83)	$ (1.00)
Diluted (in dollars per share)	$ (0.01)	$ (0.48)	$ (0.83)	$ (1.00)
Shares used to compute net loss per share:
Basic (in shares)	245,838	234,242	242,746	230,918
Diluted (in shares)	245,838	234,242	242,746	230,918