CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Income Statement [Abstract]
Revenue	$ 230,771	$ 190,103	$ 408,377	$ 374,312
Cost of goods sold	138,057	133,384	256,613	278,821
Gross profit	92,714	56,719	151,764	95,491
Operating expenses:
Research, development and engineering	48,001	47,107	97,871	93,178
Selling, general and administrative	37,316	25,989	66,479	53,230
Total operating expenses	85,317	73,096	164,350	146,408
Income (loss) from operations	7,397	(16,377)	(12,586)	(50,917)
Other (expense) income :
Interest income	42	38	69	76
Interest expense	(844)	(1,137)	(1,699)	(2,276)
Other, net	(624)	336	(579)	27
Total other expense, net	(1,426)	(763)	(2,209)	(2,173)
Income (loss) before income tax	5,971	(17,140)	(14,795)	(53,090)
Income tax expense (benefit)	761	(2,255)	(936)	(10,256)
Net income (loss)	5,210	(14,885)	(13,859)	(42,834)
Net earnings (loss) per common share:
Basic	$ 0.03	$ (0.09)	$ (0.08)	$ (0.27)
Diluted	$ 0.03	$ (0.09)	$ (0.08)	$ (0.27)
Common equivalent shares:
Basic	171,770	159,347	168,140	160,044
Diluted	181,319	159,347	168,140	160,044
Other comprehensive income (loss):
Net unrealized loss on available for sale investments	(2)	(4)	(2)	(2)
Comprehensive income (loss)	$ 5,208	$ (14,889)	$ (13,861)	$ (42,836)