Shareowners' Equity - Common Stock (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Shareowners' Equity (Textuals) [Abstract]
Common stock, authorized (in shares)	1,000,000,000,000,000,000
Common stock, par value (in dollars per share)	$ 1.00	$ 1
Preferred stock, authorized (in shares)	25,000,000
Common stock reserved for various incentive plans (in shares)	17,300,000
Outstanding purchase of common stock recorded in accounts payable	$ 0	$ 9,300,000
Changes in outstanding common shares
Beginning balance (in shares)	115,700,000	121,000,000.0	128,400,000
Treasury stock purchases (in shares)	(1,400,000)	(6,100,000)	(8,300,000)
Common stock issued (including share based compensation impact) (in shares)	1,900,000	800,000	900,000
Ending balance (in shares)	116,200,000	115,700,000	121,000,000.0