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. 27, 2019	Sep. 28, 2018
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract]
Number of Shares (in shares)	2.2	2.3
Weighted Average Remaining Contractual Term (in years)	4 years 7 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 97.66	$ 85.82
Aggregate Intrinsic Value	$ 50.0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	1.2	3.7
Weighted Average Remaining Contractual Term (in years)	3 years 6 months
Weighted Average Exercise Price (in dollars per share)	$ 80.98	$ 74.14
Aggregate Intrinsic Value	$ 42.8
Closing price (in dollars per share)	$ 118.16
$60.91 - $77.49
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	60.91
Range of Exercise Prices, Upper (in dollars per share)	$ 77.49
Number of Shares (in shares)	0.4
Weighted Average Remaining Contractual Term (in years)	2 years 9 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 68.12
Aggregate Intrinsic Value	$ 22.4
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.5
Weighted Average Remaining Contractual Term (in years)	2 years 9 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 68.12
Aggregate Intrinsic Value	$ 22.4
$80.40 - $99.26
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	$ 80.40
Range of Exercise Prices, Upper (in dollars per share)	$ 99.26
Number of Shares (in shares)	0.6
Weighted Average Remaining Contractual Term (in years)	3 years 7 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 81.66
Aggregate Intrinsic Value	$ 22.5
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.5
Weighted Average Remaining Contractual Term (in years)	3 years 6 months
Weighted Average Exercise Price (in dollars per share)	$ 81.34
Aggregate Intrinsic Value	$ 19.4
$107.32 - $118.27
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	$ 107.32
Range of Exercise Prices, Upper (in dollars per share)	$ 118.27
Number of Shares (in shares)	0.7
Weighted Average Remaining Contractual Term (in years)	5 years 6 months
Weighted Average Exercise Price (in dollars per share)	$ 111.07
Aggregate Intrinsic Value	$ 5.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Number of Shares (in shares)	0.2
Weighted Average Remaining Contractual Term (in years)	5 years 3 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 112.66
Aggregate Intrinsic Value	$ 1.0
$118.76 - $131.77
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract]
Range of Exercise Prices, Lower (in dollars per share)	$ 118.76
Range of Exercise Prices, Upper (in dollars per share)	$ 131.77
Number of Shares (in shares)	0.5
Weighted Average Remaining Contractual Term (in years)	6 years 3 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 127.10
Aggregate Intrinsic Value	$ 0.0
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)	0 years
Weighted Average Exercise Price (in dollars per share)	$ 0
Aggregate Intrinsic Value	$ 0.0

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Price of a single share of a number of saleable stocks of a company.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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