Other Deductions, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Other Income and Expenses [Abstract]
Amortization of intangibles (intellectual property and customer relationships)	$ 136	$ 84	$ 94
Restructuring costs	78	96	138
Other	72	114	98
Total	286	294	$ 330
Change in gain (loss) from foreign currency transactions	78	(67)
Acquisition and divestiture related costs	$ 24
Change in litigation costs (increase) decrease		30
Dumping duties received		$ 21