Common and Preferred Stock (Details) - $ / shares	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Class of Stock Disclosures [Abstract]
Shares of common stock reserved for issuance under stock-based compensation plans	37,000,000
Common shares repurchased	15,100,000	6,600,000
Treasury shares re-issued	2,600,000	5,500,000
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