Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Financial information related to Company's reportable segments
Net Sales	$ 10,364	$ 8,540	$ 30,045	$ 25,265
Segment Income	512	496	1,566	1,329
Net financing charges	(43)	(39)	(124)	(117)
Income before income taxes	469	457	1,442	1,212
Segment Information (Textuals)
Number of reportable segments			9
Number of primary businesses			3
Building Efficiency [Member]
Financial information related to Company's reportable segments
Net Sales	3,893	3,217	10,805	9,208
Segment Income	207	190	478	398
Segment Information (Textuals)
Number of reportable segments prior to reorganization			6
Number of reportable segments			5
Building Efficiency [Member] | Other [Member]
Financial information related to Company's reportable segments
Net Sales	1,115	999	3,068	2,759
Segment Income	30	51	45	67
Building Efficiency [Member] | Asia [Member]
Financial information related to Company's reportable segments
Net Sales	498	349	1,334	988
Segment Income	69	47	178	119
Building Efficiency [Member] | North America systems [Member]
Financial information related to Company's reportable segments
Net Sales	633	551	1,711	1,552
Segment Income	66	61	169	144
Building Efficiency [Member] | North America service [Member]
Financial information related to Company's reportable segments
Net Sales	601	531	1,639	1,505
Segment Income	35	25	69	50
Building Efficiency [Member] | Global workplace solutions [Member]
Financial information related to Company's reportable segments
Net Sales	1,046	787	3,053	2,404
Segment Income	7	6	17	18
Automotive Experience [Member]
Financial information related to Company's reportable segments
Net Sales	5,118	4,213	14,927	12,482
Segment Income	142	171	530	481
Automotive Experience [Member] | Europe [Member]
Financial information related to Company's reportable segments
Net Sales	2,800	2,033	7,693	6,238
Segment Income	24	49	40	110
Automotive Experience [Member] | North America [Member]
Financial information related to Company's reportable segments
Net Sales	1,772	1,740	5,517	4,981
Segment Income	67	97	328	293
Automotive Experience [Member] | Asia [Member]
Financial information related to Company's reportable segments
Net Sales	546	440	1,717	1,263
Segment Income	51	25	162	78
Power Solutions [Member]
Financial information related to Company's reportable segments
Net Sales	1,353	1,110	4,313	3,575
Segment Income	$ 163	$ 135	$ 558	$ 450