Employee Stock and Benefit Plans (Narrative) (Details) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
	Apr. 09, 2015 $ / shares	Sep. 27, 2015 USD ($) $ / shares shares	Sep. 28, 2014 USD ($) $ / shares	Sep. 29, 2013 USD ($) $ / shares
Class of Stock [Line Items]
Stock split conversion ratio	2
Common stock, par value | $ / shares		$ 0.001	$ 0.001
Maximum permitted contribution to Employee Stock Purchase Plan, percent		10.00%
Discounted stock purchase price, percent of market value		95.00%
Number of shares issued under plan | shares		0.5
Matching contributions		$ 70.9	$ 73.0	$ 54.7
Stock Options and Restricted Stock Units [Member]
Common stock available for issuance | shares		96.3
Employee Stock [Member]
Common stock available for issuance | shares		14.3
Stock Options [Member]
Award expiration period (years)		10 years
Total unrecognized stock-based compensation expense, net of estimated forfeitures		$ 32.0
Weighted average recognition period for total unrecognized stock-based compensation expense (in years)		2 years 7 months 3 days
Total intrinsic value of stock options exercised		$ 358.0	258.0	539.0
Total fair value of options vested		36.0	$ 44.0	$ 56.0
Restricted Stock Units (RSUs) [Member]
Total unrecognized stock-based compensation expense, net of estimated forfeitures		$ 126.0
Weighted average recognition period for total unrecognized stock-based compensation expense (in years)		2 years 3 months 3 days
Granted, weighted average grant date fair value per share | $ / shares		$ 38.56	$ 40.07	$ 25.12
Total fair value of RSUs vested		$ 137.0	$ 103.0	$ 104.0
Director [Member] | Stock Options [Member] | Minimum [Member]
Award vesting period for non-employee directors (years)		1 year
Director [Member] | Stock Options [Member] | Maximum [Member]
Award vesting period for non-employee directors (years)		3 years
Common Stock [Member]
Class of Stock [Line Items]
Stock split conversion ratio	2
Common stock, par value | $ / shares	$ 0.001