Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax			$ (1,368)	$ (1,150)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax			(15)	(49)
Accumulated Other Comprehensive Income (Loss) Other			(1)	(1)
Accumulated other comprehensive loss			(1,384)	(1,200)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax			(99)	0
Other comprehensive loss before reclassifications			39	52
Other Comprehensive Income (Loss), Tax			(1)	(18)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax			(10)	51
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax			0	0
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax			0	0
Other Comprehensive Income (Loss), Other, Before Reclassification and Tax			0	0
Other Comprehensive Income (Loss), Other, Tax			0	0
Other Comprehensive Income (Loss), before Tax	$ 10	$ 17	39	52
Other Comprehensive Income (Loss), Before Reclassification and Tax			(109)	51
Other Comprehensive Income (Loss), Tax			(1)	(18)
Other Comprehensive Income (Loss), Other, Before Tax			0	0
Accumulated other comprehensive loss	(1,455)	(1,115)	(1,455)	(1,115)
Accumulated Other Comprehensive Income (Loss) Other	(1)	(1)	(1)	(1)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(25)	2	(25)	2
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(1,429)	(1,116)	(1,429)	(1,116)
Costs - Products
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss before reclassifications	3	4	10	13
Costs - Services
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss before reclassifications	3	4	10	13
Selling, general and administrative
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss before reclassifications	4	8	17	22
Research and development
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss before reclassifications	$ 0	$ 1	$ 2	$ 4