Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Apr. 01, 2016	Mar. 31, 2017	Apr. 01, 2016
Income Statement [Abstract]
Net revenue	$ 851.7	$ 775.1	$ 1,766.0	$ 1,701.9
Cost of goods sold	426.3	384.7	876.7	839.4
Gross profit	425.4	390.4	889.3	862.5
Operating expenses:
Research and development	89.4	79.8	171.4	161.3
Selling, general and administrative	47.8	44.0	98.7	95.7
Amortization of intangibles	7.0	8.6	15.5	17.0
Restructuring and other charges	0.0	0.3	0.6	0.3
Total operating expenses	144.2	132.7	286.2	274.3
Operating income	281.2	257.7	603.1	588.2
Other income (expense), net	0.2	(2.6)	(0.6)	(3.4)
Merger termination fee	0.0	0.0	0.0	88.5
Income before income taxes	281.4	255.1	602.5	673.3
Provision for income taxes	56.5	47.0	119.8	109.9
Net income	$ 224.9	$ 208.1	$ 482.7	$ 563.4
Earnings per share:
Basic (in dollars per share)	$ 1.22	$ 1.09	$ 2.61	$ 2.96
Diluted (in dollars per share)	$ 1.20	$ 1.08	$ 2.58	$ 2.90
Weighted average shares:
Basic (in shares)	184.8	190.2	184.8	190.3
Diluted (in shares)	187.1	193.3	187.2	194.0
Cash dividends declared and paid per share (usd per share)	$ 0.28	$ 0.26	$ 0.56	$ 0.52