CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Income Statement [Abstract]
Product revenue	$ 86,528	$ 96,777	$ 174,788	$ 179,252
Service revenue	23,061	20,351	42,833	39,548
Net revenue	109,589	117,128	217,621	218,800
Product cost of revenue	47,928	48,932	92,534	94,169
Service cost of revenue	11,844	10,304	22,958	20,574
Total cost of revenue	59,772	59,236	115,492	114,743
Gross profit	49,817	57,892	102,129	104,057
Operating expenses:
Research and development	23,485	25,820	47,373	51,071
Selling, general and administrative	32,979	34,424	66,526	67,693
Amortization of intangibles	1,718	2,010	3,668	4,098
Restructuring and related charges	284	242	433	666
Total operating expenses	58,466	62,496	118,000	123,528
Loss from operations	(8,649)	(4,604)	(15,871)	(19,471)
Interest income, net	67	30	144	94
Other expense, net	(127)	(133)	(115)	(300)
Loss from continuing operations before income taxes	(8,709)	(4,707)	(15,842)	(19,677)
Provision for (benefit from) income taxes	28,353	(1,303)	26,630	(6,770)
Loss from continuing operations	(37,062)	(3,404)	(42,472)	(12,907)
Income (loss) from discontinued operations, net of taxes (including gain on disposal of $14,819, net of taxes, for the six months ended June 28, 2013)	0	(396)	0	15,528
Net income (loss)	$ (37,062)	$ (3,800)	$ (42,472)	$ 2,621
Earnings Per Share, Basic and Diluted [Abstract]
Continuing Operations	$ (0.39)	$ (0.03)	$ (0.44)	$ (0.11)
Discontinued Operations	$ 0.00	$ 0.00	$ 0.00	$ 0.14
Net income (loss)	$ (0.39)	$ (0.03)	$ (0.44)	$ 0.02
Shares used in per share calculation:
Basic and Diluted	93,966	109,938	95,899	112,534