Long-Lived Net Property, Equipment and Technology Assets Classified by Major Geographic Area (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Property, equipment and technology, net	$ 2,150	$ 1,888
United States
Segment Reporting Information [Line Items]
Property, equipment and technology, net	1,827	1,806
Countries Outside of United States
Segment Reporting Information [Line Items]
Property, equipment and technology, net	$ 323	$ 82