Shareowners' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Shareowners' Equity (Textuals) [Abstract]
Common stock, authorized	1,000.0
Common stock, par value	$ 1.00	$ 1.00
Preferred stock, authorized	25.0
Preferred stock, par value	$ 0
Common stock reserved for various incentive plans	10.8
Outstanding purchase of common stock recorded in accounts payable	$ 0.0	$ 5.3
Changes in outstanding common shares
Beginning balance	128.5	132.4	136.7
Treasury stock purchases	(2.3)	(4.6)	(5.4)
Shares delivered under incentive plans	2.2	0.7	1.1
Ending balance	128.4	128.5	132.4