Segment Data - Revenues to Unaffiliated Customers and Long-lived Assets Including Property, Plant and Equipment (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 3,166	$ 3,035	$ 2,969	$ 2,922	$ 3,231	$ 3,198	$ 3,067	$ 2,986	$ 12,093	$ 12,483	$ 10,282
Long-Lived Assets	19,101				19,220				19,101	19,220	20,819
Corporate
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	366				329				366	329	332
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									6,504	6,893	5,069
Long-Lived Assets	13,151				14,075				13,151	14,075	15,513
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,588	2,674	2,434
Long-Lived Assets	4,421				3,747				4,421	3,747	3,908
Greater Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,744	1,692	1,545
Long-Lived Assets	578				586				578	586	573
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,257	1,225	1,234
Long-Lived Assets	$ 584				$ 483				$ 584	$ 483	$ 494