Goodwill and Other Intangible Assets Changes in Carrying Amount of Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 6,589	$ 6,982
Business Acquisitions	979	266
Business Divestitures	(265)	(266)
Impairments	(47)	(430)
Currency Translation and Other	(129)	37
Goodwill, Ending Balance	7,127	6,589
Power Solutions
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,054	1,040
Business Acquisitions	106	0
Business Divestitures	0	0
Impairments	0	0
Currency Translation and Other	(18)	14
Goodwill, Ending Balance	1,142	1,054
North America Systems | Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,228	1,229
Business Acquisitions	0	0
Business Divestitures	0	0
Impairments	0	0
Currency Translation and Other	(1)	(1)
Goodwill, Ending Balance	1,227	1,228
Global Workplace Solutions | Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance	257	187
Business Acquisitions	0	79
Business Divestitures	(253)	0
Impairments	0	0
Currency Translation and Other	(4)	(9)
Goodwill, Ending Balance	0	257
Building Efficiency Asia | Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance	388	396
Business Acquisitions	34	0
Business Divestitures	0	0
Impairments	0	0
Currency Translation and Other	(8)	(8)
Goodwill, Ending Balance	414	388
Building Efficiency Other | Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,003	994
Business Acquisitions	837	0
Business Divestitures	0	0
Impairments	(47)	0
Currency Translation and Other	(5)	9
Goodwill, Ending Balance	1,788	1,003
Seating | Automotive Experience
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,659	2,484
Business Acquisitions	2	187
Business Divestitures	0	(15)
Impairments	0	0
Currency Translation and Other	(105)	3
Goodwill, Ending Balance	2,556	2,659
Interiors | Automotive Experience
Goodwill [Roll Forward]
Goodwill, Beginning Balance	0	402
Business Acquisitions	0	0
Business Divestitures	(12)	0
Impairments	0	(430)
Currency Translation and Other	12	28
Goodwill, Ending Balance	0	0
Automotive Experience Electronics | Automotive Experience
Goodwill [Roll Forward]
Goodwill, Beginning Balance		250
Business Acquisitions		0
Business Divestitures		(251)
Impairments		0
Currency Translation and Other		1
Goodwill, Ending Balance		$ 0