Common and Preferred Stock (Details) - $ / shares	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Class of Stock Disclosures [Abstract]
Shares of common stock reserved for issuance under stock-based compensation plans	34,300,000
Common shares repurchased	19,900,000	15,100,000
Treasury shares re-issued	1,800,000	2,600,000
Shares of preferred stock authorized	5,400,000	5,400,000
Par value of preferred stocked authorized	$ 2.50	$ 2.50
Shares of preferred stock issued	0	0