Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net revenue	$ 265,858	$ 269,411	$ 745,792	$ 769,888
Cost of revenue	188,666	174,966	521,147	518,844
Gross profit	77,192	94,445	224,645	251,044
Operating expenses:
Research and development	19,537	20,136	57,183	63,273
Sales and marketing	33,491	37,892	103,887	114,318
General and administrative	11,887	16,184	35,467	50,403
Other operating expenses, net	212	380	1,709	1,752
Total operating expenses	65,127	74,592	198,246	229,746
Income from operations	12,065	19,853	26,399	21,298
Interest income, net	639	985	2,122	2,806
Other income (expense), net	(403)	955	425	425
Income before income taxes	12,301	21,793	28,946	24,529
Provision (benefit) for income taxes	(228)	5,483	2,735	6,668
Net income from continuing operations	12,529	16,310	26,211	17,861
Net loss from discontinued operations, net of tax	0	(7,160)	0	(8,351)
Net income	12,529	9,150	26,211	9,510
Net Income (Loss) Attributable to Noncontrolling Interest	0	(799)	0	(799)
Net income	$ 12,529	$ 9,949	$ 26,211	$ 10,309
Net income per share - basic:
Income per share - basic, continuing operations (in dollars per share)	$ 0.41	$ 0.51	$ 0.84	$ 0.56
Income per share - basic, discontinued operations (in dollars per share)	0	(0.20)	0	(0.23)
Net income per share - basic (in dollars per share)	0.41	0.31	0.84	0.33
Net income per share - diluted:
Income per share - diluted, continuing operations (in dollars per share)	0.39	0.49	0.81	0.54
Income per share - diluted, discontinued operations (in dollars per share)	0	(0.19)	0	(0.23)
Net income per share - diluted (in dollars per share)	$ 0.39	$ 0.30	$ 0.81	$ 0.31
Weighted average shares used to compute net income per share:
Basic (in shares)	30,933	31,802	31,221	31,634
Diluted (in shares)	31,819	32,974	32,327	32,826