Employee Stock Plans - Options Outstanding and Exercisable Under Employee Stock Plans (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014	Sep. 27, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of Shares (in shares)	2.6	2.5	3.3	4.5
Weighted Average Remaining Contractual Term (in years)	4 years 8 months 27 days
Weighted Average Exercise Price (in dollars per share)	$ 78.25	$ 72.58	$ 60.53	$ 53.02
Aggregate Intrinsic Value	$ 54.4
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	1.4	1.6
Weighted Average Remaining Contractual Term (in years)	3 years 7 months 24 days
Weighted Average Exercise Price (in dollars per share)	$ 76.31	$ 62.97
Aggregate Intrinsic Value	$ 31.6
Closing price (in dollars per share)	$ 99.53
$50.66 – $57.90
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	50.66
Range of Exercise Prices, Upper (in dollars per share)	$ 57.90
Number of Shares (in shares)	0.3
Weighted Average Remaining Contractual Term (in years)	1 year 4 months 21 days
Weighted Average Exercise Price (in dollars per share)	$ 55.47
Aggregate Intrinsic Value	$ 11.5
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.3
Weighted Average Remaining Contractual Term (in years)	1 year 4 months 21 days
Weighted Average Exercise Price (in dollars per share)	$ 55.47
Aggregate Intrinsic Value	$ 11.5
$64.01 – $72.26
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	$ 64.01
Range of Exercise Prices, Upper (in dollars per share)	$ 72.26
Number of Shares (in shares)	0.3
Weighted Average Remaining Contractual Term (in years)	2 years 11 months 12 days
Weighted Average Exercise Price (in dollars per share)	$ 68.59
Aggregate Intrinsic Value	$ 10.7
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.3
Weighted Average Remaining Contractual Term (in years)	2 years 11 months 12 days
Weighted Average Exercise Price (in dollars per share)	$ 68.59
Aggregate Intrinsic Value	$ 10.7
$74.28 – $81.90
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	$ 74.28
Range of Exercise Prices, Upper (in dollars per share)	$ 81.9
Number of Shares (in shares)	0.8
Weighted Average Remaining Contractual Term (in years)	6 years 4 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 75.96
Aggregate Intrinsic Value	$ 19.6
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.0
Weighted Average Remaining Contractual Term (in years)	4 years 1 month 21 days
Weighted Average Exercise Price (in dollars per share)	$ 74.28
Aggregate Intrinsic Value	$ 0.2
$83.70 – $92.65
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	$ 83.7
Range of Exercise Prices, Upper (in dollars per share)	$ 92.65
Number of Shares (in shares)	1.2
Weighted Average Remaining Contractual Term (in years)	4 years 10 months 21 days
Weighted Average Exercise Price (in dollars per share)	$ 88.28
Aggregate Intrinsic Value	$ 12.6
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.8
Weighted Average Remaining Contractual Term (in years)	4 years 9 months 7 days
Weighted Average Exercise Price (in dollars per share)	$ 87.21
Aggregate Intrinsic Value	$ 9.2