CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Income Statement [Abstract]
Net sales	$ 292,301	$ 242,630	$ 834,948	$ 725,561
Cost of sales	138,711	104,318	394,411	311,211
Gross profit	153,590	138,312	440,537	414,350
Operating expenses:
Selling, general and administrative	61,141	48,845	181,513	152,514
Research and development costs	48,044	42,192	141,452	127,324
Amortization of intangible assets	23,422	21,045	69,694	63,865
Restructuring and severance charges	14,653	981	27,073	8,092
Total operating expenses	147,260	113,063	419,732	351,795
Operating income	6,330	25,249	20,805	62,555
Other expenses:
Interest (expense), net	(6,459)	(7,203)	(21,656)	(23,308)
Other income (expense), net	(627)	188	(2,132)	(3,361)
Total other (expense)	(7,086)	(7,015)	(23,788)	(26,669)
Income (loss) before income taxes	(756)	18,234	(2,983)	35,886
Provision (benefit) for income taxes	3,537	(45)	6,690	6,298
Net income (loss)	(4,293)	18,279	(9,673)	29,588
Earnings (loss) per share:
Basic (USD per share)	$ (0.05)	$ 0.20	$ (0.10)	$ 0.33
Diluted (USD per share)	$ (0.05)	$ 0.20	$ (0.10)	$ 0.33
Weighted-average common shares outstanding:
Basic	93,095	89,809	92,664	89,235
Diluted	93,095	91,682	92,664	90,810
Net income (loss)	(4,293)	18,279	(9,673)	29,588
Other comprehensive income (loss), net of tax:
Translation adjustment	(346)	186	100	451
Unrealized actuarial loss on pension benefits	(44)	(43)	(132)	(129)
Other comprehensive income (loss), net of tax	(390)	143	(32)	322
Total comprehensive income (loss)	$ (4,683)	$ 18,422	$ (9,705)	$ 29,910