Stockholders' Equity (Stock Options) (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Sep. 28, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance outstanding at October 2, 2015 (in shares) | shares	3.0
Granted (in shares) | shares	0.1
Exercised (in shares) | shares	(1.1)
Canceled/forfeited (in shares) | shares	(0.1)
Balance outstanding at September 30, 2016 (in shares) | shares	1.9
Shares exercisable (in shares) | shares	1.2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Stock options outstanding, weighted average exercise price, beginning balance | $ / shares	$ 50.36
Granted, weighted average exercise price | $ / shares	26.66
Exercised, weighted average exercise price | $ / shares	35.92
Canceled/forfeited, weighted average exercise price | $ / shares	72.42
Stock options outstanding, weighted average exercise price, ending balance | $ / shares	57.12
Weighted average exercise price (in dollars per share) | $ / shares	$ 50.15
Weighted average remaining contractual life, outstanding	3 years
Weighted average remaining contractual life, exercisable	2 years 3 months
Aggregate intrinsic value | $	$ 64.3
Aggregate intrinsic value | $	$ 50.8