Divestitures (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Provision for income taxes from discontinued operations				$ 22
Income from discontinued operations, net of income taxes	$ 0	$ 2	$ 0	32
Avaya Gov
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
SERVICES REVENUE		0		53
OPERATING INCOME FROM DISCONTINUED OPERATIONS		0		7
Gain on sale of ITPS business		3		52
INCOME FROM DISCONTINUED OPERATIONS BEFORE INCOME TAXES		3		59
Provision for income taxes from discontinued operations		(1)		(27)
Income from discontinued operations, net of income taxes		$ 2		$ 32