CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Income Statement [Abstract]
Revenue	$ 272,147	$ 250,836	$ 680,524	$ 625,148
Cost of goods sold	148,427	158,619	405,040	437,440
Gross profit	123,720	92,217	275,484	187,708
Operating expenses:
Research, development and engineering	49,810	47,023	147,681	140,201
Selling, general and administrative	38,035	26,420	104,514	79,650
Total operating expenses	87,845	73,443	252,195	219,851
Income (loss) from operations	35,875	18,774	23,289	(32,143)
Other (expense) income :
Interest income	92	7	161	83
Interest expense	(892)	(1,153)	(2,591)	(3,429)
Other, net	297	70	(282)	97
Total other expense, net	(503)	(1,076)	(2,712)	(3,249)
Income (loss) before income tax	35,372	17,698	20,577	(35,392)
Income tax expense (benefit)	9,188	4,137	8,252	(6,119)
Net income (loss)	26,184	13,561	12,325	(29,273)
Net earnings (loss) per common share:
Basic	$ 0.15	$ 0.09	$ 0.07	$ (0.18)
Diluted	$ 0.14	$ 0.08	$ 0.07	$ (0.18)
Common equivalent shares:
Basic	175,764	157,105	170,709	159,057
Diluted	185,701	163,917	180,302	159,057
Other comprehensive income (loss):
Net unrealized (loss) income on available for sale investments	(20)	5	(22)	3
Comprehensive income (loss)	$ 26,164	$ 13,566	$ 12,303	$ (29,270)