Segment Data - Revenues by Geographic Areas (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	$ 2,986	$ 2,051
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	1,691	881
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	$ 1,295	$ 1,170