CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Income Statement [Abstract]
Revenue	$ 404,093	$ 398,799	$ 385,961
Cost of revenue	165,671	179,360	169,382
Gross margin	238,422	219,439	216,579
Operating expenses:
Research and development	78,617	82,449	103,357
Selling, general, and administrative	82,542	91,054	90,718
Amortization of acquired intangible assets	13,558	17,690	31,340
Restructuring charges	4,664	17,349	7,196
Impairment of acquired intangible assets	0	12,486	32,431
Acquisition related charges	0	1,531	3,781
Gain on sale of building	0	0	(4,624)
Total operating expenses	179,381	222,559	264,199
Income (loss) from operations	59,041	(3,120)	(47,620)
Interest expense	(11,731)	(20,600)	(18,807)
Other expense, net	(2,245)	(249)	(3,286)
Income (loss) before income taxes	45,065	(23,969)	(69,713)
Income tax expense	1,572	2,353	849
Net income (loss)	$ 43,493	$ (26,322)	$ (70,562)
Net income (loss) per share:
Basic (in usd per share)	$ 0.33	$ (0.21)	$ (0.58)
Diluted (in usd per share)	$ 0.32	$ (0.21)	$ (0.58)
Shares used in per share calculations:
Basic (in shares)	132,471	126,564	122,677
Diluted (in shares)	137,274	126,564	122,677