Segment Data - Revenues by Geographic Areas (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	$ 2,051	$ 2,015
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	881	849
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	$ 1,170	$ 1,166