Employee Stock Plans - Activity Under Employee Stock Plans (Detail) - $ / shares shares in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Number of Shares
Beginning balance (in shares)	2.6
Granted (in shares)	0.6
Adjustment due to Distribution (in shares)	0.3
Canceled, expired or forfeited (in shares)	(0.4)
Exercised (in shares)	(0.8)
Ending balance (in shares)	2.3
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 78.25
Granted (in dollars per share)	82.29
Adjustment due to Distribution (in dollars per share)	70.15
Canceled, expired or forfeited (in dollars per share)	70.26
Exercised (in dollars per share)	66.80
Ending balance (in dollars per share)	$ 74.08
Number of Shares (in shares)	1.2	1.4
Weighted Average Exercise Price (in dollars per share)	$ 71.37	$ 76.31