CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2015	Jun. 27, 2014	Jul. 03, 2015	Jun. 27, 2014
Income Statement [Abstract]
Product revenue	$ 77,447	$ 86,528	$ 157,920	$ 174,788
Service revenue	25,656	23,061	49,199	42,833
Net revenue	103,103	109,589	207,119	217,621
Product cost of revenue	35,977	47,928	71,437	92,534
Service cost of revenue	12,741	11,844	26,269	22,958
Total cost of revenue	48,718	59,772	97,706	115,492
Gross profit	54,385	49,817	109,413	102,129
Operating expenses:
Research and development	21,816	23,485	44,145	47,373
Selling, general and administrative	31,281	32,979	62,477	66,526
Amortization of intangibles	1,446	1,718	2,892	3,668
Restructuring and related charges	185	284	229	433
Total operating expenses	54,728	58,466	109,743	118,000
Loss from operations	(343)	(8,649)	(330)	(15,871)
Interest income, net	17	67	72	144
Other income (expense), net	59	(127)	(447)	(115)
Loss on impairment of long-term investment			(2,505)	0
Loss before income taxes	(267)	(8,709)	(3,210)	(15,842)
Provision for income taxes	727	28,353	441	26,630
Net loss	$ (994)	$ (37,062)	$ (3,651)	$ (42,472)
Net loss per share:
Basic and diluted	$ (0.01)	$ (0.39)	$ (0.04)	$ (0.44)
Shares used in per share calculation:
Basic and diluted	88,426	93,966	88,541	95,899