Goodwill and Other Intangible Assets Goodwill Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Goodwill [Line Items]
Goodwill, written off related to divestiture	$ 265	$ 266
Goodwill impairment loss	47	430
Goodwill	7,127	6,589	6,982
Building Efficiency | Global Workplace Solutions
Goodwill [Line Items]
Goodwill, written off related to divestiture	253	0
Goodwill impairment loss	0	0
Goodwill	0	257	187
Building Efficiency | Building Efficiency Other
Goodwill [Line Items]
Goodwill, written off related to divestiture	0	0
Goodwill impairment loss	47	0
Goodwill	1,788	1,003	994
Building Efficiency | Assets Held-for-sale | Global Workplace Solutions
Goodwill [Line Items]
Goodwill, written off related to divestiture	253
Automotive Experience | Interiors
Goodwill [Line Items]
Goodwill, written off related to divestiture	12	0
Goodwill impairment loss	0	430
Goodwill	0	0	402
Automotive Experience | Automotive Experience Electronics
Goodwill [Line Items]
Goodwill, written off related to divestiture		251
Goodwill impairment loss		0
Goodwill		0	250
Automotive Experience | Assets Held-for-sale | Interiors
Goodwill [Line Items]
Goodwill, written off related to divestiture	12
Automotive Experience | Assets Held-for-sale | Automotive Experience Electronics
Goodwill [Line Items]
Goodwill, written off related to divestiture		74
Middle East | Building Efficiency | Building Efficiency Other
Goodwill [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	9.00%
Goodwill	$ 85