Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Sep. 30, 2015
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	$ 158	$ 160
Accumulated Amortization	(9)	(7)
Net Intangible Assets, finite lives	149	153
Developed Technologies [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	48	48
Accumulated Amortization	(2)	(1)
Net Intangible Assets, finite lives	46	47
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	15	16
Net Intangible Assets, finite lives	15	16
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	95	96
Accumulated Amortization	(7)	(6)
Net Intangible Assets, finite lives	$ 88	$ 90