Shareowners' Equity (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), Net Of Tax [Roll Forward]
Beginning balance	$ (771)	$ (734)	$ (749)	$ (734)
Other comprehensive loss before reclassification	(34)	14	(69)	4
Amounts reclassified from accumulated other comprehensive loss - net of tax	12	8	25	18
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(22)	22	(44)	22
Ending balance	(793)	(712)	(793)	(712)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net Of Tax [Roll Forward]
Beginning balance	8	51	41	61
Other comprehensive loss before reclassification	(33)	10	(67)	0
Amounts reclassified from accumulated other comprehensive loss - net of tax	0	0	1	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(33)	10	(66)	0
Ending balance	(25)	61	(25)	61
Employee Benefit Related Adjustments
Accumulated Other Comprehensive Income (Loss), Net Of Tax [Roll Forward]
Beginning balance	(777)	(782)	(789)	(792)
Other comprehensive loss before reclassification	(1)	2	(1)	2
Amounts reclassified from accumulated other comprehensive loss - net of tax	12	8	24	18
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	11	10	23	20
Ending balance	(766)	(772)	(766)	(772)
Unrealized Loss, net of tax
Accumulated Other Comprehensive Income (Loss), Net Of Tax [Roll Forward]
Beginning balance	(2)	(3)	(1)	(3)
Other comprehensive loss before reclassification	0	2	(1)	2
Amounts reclassified from accumulated other comprehensive loss - net of tax	0	0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	0	2	(1)	2
Ending balance	$ (2)	$ (1)	$ (2)	$ (1)