Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Oct. 02, 2016	Sep. 27, 2015	Sep. 28, 2014
Income Statement [Abstract]
Net sales	$ 1,655.0	$ 1,245.6	$ 1,138.3
Cost of sales	717.9	561.3	526.8
Gross profit	937.1	684.3	611.5
Operating expenses:
Selling, general and administrative	352.4	249.5	241.0
Research and development costs	309.1	200.3	192.0
Amortization of intangible assets	161.2	96.5	92.8
Restructuring and severance charges	60.7	15.4	31.5
Total operating expenses	883.4	561.7	557.3
Operating income	53.7	122.6	54.2
Interest Income (Expense), Net	(120.1)	(27.3)	(27.8)
Other income (expenses):
Other, net	41.0	1.6	(2.5)
Total other expense	(79.1)	(25.7)	(30.3)
Income (loss) before income taxes	(25.4)	96.9	23.9
Income Tax Expense (Benefit)	7.2	12.3	0.8
Net income (loss)	$ (32.6)	$ 84.6	$ 23.1
Earnings (loss) per share:
Basic	$ (0.31)	$ 0.90	$ 0.25
Diluted	$ (0.31)	$ 0.88	$ 0.24
Weighted-average common shares outstanding:
Basic	107.0	94.2	92.9
Diluted	107.0	95.9	94.5
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Translation adjustment	$ 4.8	$ (1.6)	$ (0.5)
Unrealized actuarial loss on pension benefits	(3.9)	(0.3)	(0.7)
Other comprehensive income (loss)	0.9	(1.9)	(1.2)
Total comprehensive income (loss)	$ (31.7)	$ 82.7	$ 21.9