Amount of credit facility retired.

No definition available.

Name:	jci_AmountOfCreditFacilityRetired
Namespace Prefix:	jci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of Credit Facilities Expired

+ References

No definition available.

+ Details

Name:	jci_AmountofCreditFacilitiesExpired
Namespace Prefix:	jci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of ten-month floating rate term loans maturing in Oct 2016

+ References

No definition available.

+ Details

Name:	jci_NumberoftenmonthfloatingratetermloansmaturinginOct2016
Namespace Prefix:	jci_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13)(2))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_CommercialPaper
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Weighted average interest rate of short-term debt outstanding.

+ References

+ Details

Name:	us-gaap_ShortTermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A150millioneurofloatingratetermloanmaturinginSep2018Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A150millionUSDrevolvingcreditfacilitymaturinginMar2018Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A150millionUSDrevolvingcreditfacilitymaturinginFeb2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A250millionUSDrevolvingcreditfacilitymaturinginJan2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A100millioneurofloatingratetermloanmaturinginDec2017Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A100MillionUSDRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A100MillionUSDfloatingratetermloanmaturinginNov2016Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A100millioneurofloatingratetermloanmaturinginOct2016Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A35MillionUSDRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A325millionUSDfloatingratetermloansmaturinginOct2016Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	jci_LineOfCreditFacilityByExpirationAxis=jci_CommittedFiveYearCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=jci_ContingentonconsumationofTycomergerDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A2.0billionUSDrevolvingcreditfacilityDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=jci_TycoInternationalHoldingS.a.r.L.TSarLMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A1.0billionUSDrevolvingcreditfacilityDomainMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt and Financing Arrangements Short-Term Debt (Details)	3 Months Ended			12 Months Ended
	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 EUR (€)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 EUR (€)	Mar. 31, 2016 USD ($)
Short-term Debt [Line Items]
Short-term Debt				$ 1,214,000,000	$ 1,078,000,000
Short-term Debt, Weighted Average Interest Rate				1.60%	1.10%	1.60%
Amount Of Credit Facility Retired \| €						€ 390,000,000
Number of ten-month floating rate term loans maturing in Oct 2016		2	2
Commercial Paper [Member]
Short-term Debt [Line Items]
Commercial Paper				$ 954,000,000	$ 440,000,000
150 million euro floating rate, term loan maturing in Sep 2018 [Domain]
Short-term Debt [Line Items]
Debt Instrument, Term	364 days
Debt instrument, face amount \| €						€ 150,000,000
150 million USD revolving credit facility maturing in Mar 2018 [Domain]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 150,000,000
Debt Instrument, Term	364 days
Proceeds from Lines of Credit	$ 0
150 million USD revolving credit facility maturing in Feb 2018 [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 150,000,000
Debt Instrument, Term	364 days
Proceeds from Lines of Credit	$ 0
250 million USD revolving credit facility maturing in Jan 2018 [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 250,000,000
Debt Instrument, Term	364 days
Proceeds from Lines of Credit	$ 0
100 million euro floating rate term loan maturing in Dec 2017 [Domain]
Short-term Debt [Line Items]
Debt Instrument, Term		364 days	364 days
Debt instrument, face amount \| €			€ 100,000,000
100 Million USD Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Amount of Credit Facilities Expired		$ 100,000,000
Proceeds from Lines of Credit		$ 0
100 Million USD floating rate term loan maturing in Nov 2016 [Domain]
Short-term Debt [Line Items]
Debt Instrument, Term		9 months	9 months
Debt retired, amount		$ 100,000,000
100 million euro floating rate term loan maturing in Oct 2016 [Domain]
Short-term Debt [Line Items]
Debt Instrument, Term		9 months	9 months
Debt retired, amount \| €			€ 100,000,000
35 Million USD Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Amount of Credit Facilities Expired		$ 35,000,000
Proceeds from Lines of Credit		$ 0
325 million USD floating rate term loans maturing in Oct 2016 [Domain]
Short-term Debt [Line Items]
Debt Instrument, Term		10 months	10 months
Debt retired, amount		$ 325,000,000
Committed Five-year Credit Facility
Short-term Debt [Line Items]
Amount Of Credit Facility Retired					2,500,000,000
Debt Instrument, Term	5 years
Contingent on consumation of Tyco merger [Domain] \| 2.0 billion USD revolving credit facility [Domain]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 2,000,000,000
Debt Instrument, Term				4 years
Proceeds from Lines of Credit				$ 0	0
Tyco International Holding S.a.r.L. (TSarL) [Member] \| 1.0 billion USD revolving credit facility [Domain] [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					$ 1,000,000,000
Debt Instrument, Term	4 years