Significant Restructuring Costs Change in Restructuring Reserve - 2016 Restructuring Plan (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 102		$ 0	$ 331	$ 0
2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	102	$ 229
Payments for Restructuring	(5)	(4)
Restructuring Reserve, Settled without Cash	(53)	(27)
Restructuring Reserve	242	198		242
2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						$ 397
Payments for Restructuring				(72)		0
Restructuring Reserve, Settled without Cash				0		(183)
Restructuring Reserve	142			142		214
Employee Severance | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	35	194
Payments for Restructuring	(5)	(3)
Restructuring Reserve, Settled without Cash	0	0
Restructuring Reserve	221	191		221
Employee Severance | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						191
Payments for Restructuring				(49)		0
Restructuring Reserve, Settled without Cash				0		0
Restructuring Reserve	142			142		191
Fixed Asset Impairment | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	51	29
Payments for Restructuring	0	0
Restructuring Reserve, Settled without Cash	(51)	(29)
Restructuring Reserve	0	0		0
Fixed Asset Impairment | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						183
Payments for Restructuring				0		0
Restructuring Reserve, Settled without Cash				0		(183)
Restructuring Reserve	0			0		0
Other Restructuring | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	16	6
Payments for Restructuring	0	(1)
Restructuring Reserve, Settled without Cash	0	0
Restructuring Reserve	21	5		21
Other Restructuring | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						23
Payments for Restructuring				(23)		0
Restructuring Reserve, Settled without Cash				0		0
Restructuring Reserve	0			0		23
Currency Translation | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Payments for Restructuring	0	0
Restructuring Reserve, Settled without Cash	(2)	(2)
Restructuring Reserve	0	2		0
Currency Translation | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						0
Payments for Restructuring				0		0
Restructuring Reserve, Settled without Cash				0		0
Restructuring Reserve	0			0		0
Continuing Operations | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 102	$ 229		331
Continuing Operations | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						397
Continuing Operations | Building Efficiency Systems and Service North America | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				2
Continuing Operations | Building Efficiency Systems and Service North America | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						3
Continuing Operations | Automotive Experience Seating [Member] | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				196
Continuing Operations | Automotive Experience Seating [Member] | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						182
Continuing Operations | Building Efficiency Asia | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				26
Continuing Operations | Building Efficiency Asia | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						11
Continuing Operations | Automotive Experience Interiors | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				17
Continuing Operations | Building Efficiency Rest of World [Member] | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				16
Continuing Operations | Building Efficiency Rest of World [Member] | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						13
Continuing Operations | Building Efficiency Products North America | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				9
Continuing Operations | Building Efficiency Products North America | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						11
Continuing Operations | Corporate Segment | 2016 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 65
Continuing Operations | Corporate Segment | 2015 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						$ 166