Financial Information by Segment & Geographic Area - Revenue from External Customers and Long-Lived Asset Information by Geographic Area (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 from external customers	$ 723	$ 705	$ 678	$ 611	$ 619	$ 621	$ 568	$ 603	$ 2,717	$ 2,411	$ 2,871
Net property, plant and equipment	1,305				1,290				1,305	1,290	1,383
U.S [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues from external customers									645	605	705
Net property, plant and equipment	493				490				493	490	480
China [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues from external customers									573	482	548
Net property, plant and equipment	261				266				261	266	311
The Netherlands [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues from external customers									162	162	176
Net property, plant and equipment	161				152				161	152	157
Other Foreign Countries [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues from external customers									1,337	1,162	1,442
Net property, plant and equipment	$ 390				$ 382				$ 390	$ 382	$ 435