CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Dec. 29, 2013	Dec. 30, 2012
Income Statement [Abstract]
Net sales	$ 255,631	$ 247,598
Cost of sales	117,323	105,025
Gross profit	138,308	142,573
Operating expenses:
Selling, general and administrative	57,407	51,353
Research and development costs	44,125	43,176
Amortization of intangible assets	21,963	21,710
Restructuring and severance charges	7,653	850
Total operating expenses	131,148	117,089
Operating income	7,160	25,484
Other income (expenses):
Interest expense, net	(7,582)	(8,361)
Other, net	(314)	54
Total other expense	(7,896)	(8,307)
Income (loss) before income taxes	(736)	17,177
Provision for (benefit from) income taxes	(2,115)	2,963
Net income	1,379	14,214
Earnings per share:
Basic (USD per share)	$ 0.01	$ 0.16
Diluted (USD per share)	$ 0.01	$ 0.16
Weighted-average common shares outstanding:
Basic	92,102	88,535
Diluted	93,527	90,062
Net income	1,379	14,214
Other comprehensive income, net of tax:
Translation adjustment	280	230
Unrealized actuarial loss on pension benefits	(44)	(44)
Other comprehensive income, net of tax	236	186
Total comprehensive income	$ 1,615	$ 14,400