Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=64834752&loc=SL49117168-202975

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

+ Details

Name:	us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

+ Details

Name:	us-gaap_GoodwillForeignCurrencyTranslationGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_GoodwillRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

+ Details

Name:	us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	jci_PrimaryBusinessInformationByPrimaryBusinessAxis=jci_PowerSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_BuildingEfficiencySystemsandServiceNorthAmericaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	jci_PrimaryBusinessInformationByPrimaryBusinessAxis=jci_BuildingEfficiencyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_BuildingEfficiencyProductsNorthAmericaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_BuildingEfficiencyAsiaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_BuildingEfficiencyRestofWorldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_BuildingsTycoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_SeatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	jci_PrimaryBusinessInformationByPrimaryBusinessAxis=jci_AutomotiveExperienceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jci_InteriorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Goodwill and Other Intangible Assets Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Sep. 30, 2014	Sep. 30, 2016	Sep. 30, 2015
Goodwill [Roll Forward]
Goodwill, Beginning Balance			$ 6,824	$ 7,127
Business Acquisitions			16,622	43
Business Divestitures			(19)	(29)
Currency Translation and Other			(18)	(317)
Goodwill, Ending Balance		$ 7,127	23,409	6,824
Power Solutions
Goodwill [Roll Forward]
Goodwill, Beginning Balance			1,082	1,142
Business Acquisitions			0	0
Business Divestitures			0	0
Currency Translation and Other			4	(60)
Goodwill, Ending Balance		1,142	1,086	1,082
Building Efficiency Systems and Service North America [Member]
Goodwill [Roll Forward]
Business Divestitures	$ (3)
Building Efficiency Systems and Service North America [Member] \| Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance			978	982
Business Acquisitions			0	0
Business Divestitures			(3)	(2)
Currency Translation and Other			0	(2)
Goodwill, Ending Balance		982	975	978
Building Efficiency Products North America [Member] \| Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance			1,701	1,688
Business Acquisitions			0	34
Business Divestitures			(3)	(14)
Currency Translation and Other			(1)	(7)
Goodwill, Ending Balance		1,688	1,697	1,701
Building Efficiency Asia \| Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance			389	414
Business Acquisitions			253	0
Business Divestitures			0	0
Currency Translation and Other			15	(25)
Goodwill, Ending Balance		414	657	389
Building Efficiency Other \| Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance			310	345
Business Acquisitions			5	0
Business Divestitures			(13)	0
Impairments		(47)
Currency Translation and Other			(1)	(35)
Goodwill, Ending Balance		345	301	310
Buildings Tyco [Member] \| Building Efficiency
Goodwill [Roll Forward]
Goodwill, Beginning Balance			0
Business Acquisitions			16,364
Business Divestitures			0
Currency Translation and Other			(56)
Goodwill, Ending Balance			16,308	0
Seating \| Automotive Experience
Goodwill [Roll Forward]
Goodwill, Beginning Balance			2,364	2,556
Business Acquisitions			0	0
Business Divestitures			0	(4)
Currency Translation and Other			21	(188)
Goodwill, Ending Balance		2,556	2,385	2,364
Interiors \| Automotive Experience
Goodwill [Roll Forward]
Goodwill, Beginning Balance			$ 0	0
Business Acquisitions				9
Business Divestitures				(9)
Currency Translation and Other				0
Goodwill, Ending Balance		$ 0		$ 0