CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 30, 2012
Income Statement [Abstract]
Net sales	$ 1,138,263	$ 975,944	$ 1,012,495
Cost of sales	526,760	418,756	459,872
Gross profit	611,503	557,188	552,623
Operating expenses:
Selling, general and administrative	240,946	202,468	212,338
Research and development costs	192,013	170,573	168,516
Amortization of intangible assets	92,809	84,819	104,756
Restructuring and severance charges	31,504	9,901	8,666
Total operating expenses	557,272	467,761	494,276
Operating income	54,231	89,427	58,347
Interest Income (Expense), Net	(27,759)	(30,238)	(39,553)
Other income (expenses):
Other, net	(2,556)	(3,126)	(33,519)
Total other expense	(30,315)	(33,364)	(73,072)
Income (loss) before income taxes	23,916	56,063	(14,725)
Income Tax Expense (Benefit)	793	12,389	14,950
Net income (loss)	23,123	43,674	(29,675)
Earnings (loss) per share:
Basic	$ 0.25	$ 0.49	$ (0.35)
Diluted	$ 0.24	$ 0.48	$ (0.35)
Weighted-average common shares outstanding:
Basic	92,891	89,508	85,837
Diluted	94,511	91,328	85,837
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Translation adjustment	(552)	913	(373)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Actuarial Gain (Loss), before Tax	(671)
Unrealized actuarial loss on pension benefits		(218)	(1,156)
Other comprehensive income (loss)	(1,223)	695	(1,529)
Total comprehensive income (loss)	$ 21,900	$ 44,369	$ (31,204)