Stockholder's Equity (Share Repurchase) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended	6 Months Ended
	Jan. 31, 2018	Mar. 30, 2018	Mar. 30, 2018
Equity, Class of Treasury Stock [Line Items]
Share repurchase authorized date	Jan. 31, 2018
Authorized amount of stock for repurchase	$ 1,000.0
Stock repurchase program expiration date	Jan. 31, 2020
Stock repurchased		$ 111.8	$ 284.2
Stock repurchased (shares)		1.0	2.7
Average price of stock repurchased (in dollars per share)		$ 109.22	$ 106.32
Remaining amount authorized fro stock repurchase		$ 888.2	$ 888.2