Shareowners' Equity (Reclassifications from AOCI) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
INCOME FROM CONTINUING OPERATIONS	$ 39		$ 3		$ 72	$ 17
Provision for income taxes	(6)		(8)	[1]	(13)	(19)
NET INCOME	43		3		73	16
Amount Reclassified from Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
NET INCOME			8		25	18
Amount Reclassified from Accumulated Other Comprehensive Income | Employee Benefit Related Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Prior service costs			(2)			(4)
Actuarial losses	12	[2]	11		24	23
INCOME FROM CONTINUING OPERATIONS	12		9		24	19
Provision for income taxes	0		(1)		0	(1)
NET INCOME	12		8		24	18
Amount Reclassified from Accumulated Other Comprehensive Income | Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other reclassification adjustment					1
INCOME FROM CONTINUING OPERATIONS					1
Provision for income taxes					0
NET INCOME					$ 1

[1] Amounts for prior periods have been recast for discontinued operations.

[2] These accumulated other comprehensive income components are included in the computation of net periodic pension and retiree medical expense (see Note 18 for additional details).