CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 30, 2014	Mar. 31, 2013	Mar. 30, 2014	Mar. 31, 2013
Income Statement [Abstract]
Net sales	$ 287,016	$ 235,333	$ 542,647	$ 482,931
Cost of sales	138,377	101,868	255,700	206,893
Gross profit	148,639	133,465	286,947	276,038
Operating expenses:
Selling, general and administrative	62,965	52,316	120,372	103,669
Research and development costs	49,283	41,956	93,408	85,132
Amortization of intangible assets	24,309	21,110	46,272	42,820
Restructuring and severance charges	4,767	6,261	12,420	7,111
Total operating expenses	141,324	121,643	272,472	238,732
Operating income	7,315	11,822	14,475	37,306
Other expenses:
Interest expense, net	(7,615)	(7,744)	(15,197)	(16,105)
Other expense, net	(1,191)	(3,603)	(1,505)	(3,549)
Total other expense	(8,806)	(11,347)	(16,702)	(19,654)
Income (loss) before income taxes	(1,491)	475	(2,227)	17,652
Provision for income taxes	5,268	3,380	3,154	6,343
Net income (loss)	(6,759)	(2,905)	(5,381)	11,309
Earnings (loss) per share:
Basic (USD per share)	$ (0.07)	$ (0.03)	$ (0.06)	$ 0.13
Diluted (USD per share)	$ (0.07)	$ (0.03)	$ (0.06)	$ 0.12
Weighted-average common shares outstanding:
Basic	92,805	89,405	92,455	88,970
Diluted	92,805	89,405	92,455	90,538
Net income (loss)	(6,759)	(2,905)	(5,381)	11,309
Other comprehensive income (loss), net of tax:
Translation adjustment	122	35	446	265
Unrealized actuarial loss on pension benefits	(44)	(42)	(88)	(86)
Other comprehensive income (loss), net of tax	78	(7)	358	179
Total comprehensive income (loss)	$ (6,681)	$ (2,912)	$ (5,023)	$ 11,488