Bank term loans outstanding

No definition available.

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

- Definition

Line of Credit, Borrowing Capacity, Terminated

+ References

No definition available.

+ Details

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

- Definition

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

+ References

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-Topic 835
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
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+ Details

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

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A2.5billionfacilityexpiringDec2024Domain
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- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A500millionfacilityexpiringDec2020Domain
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Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=jci_A2BillionCommittedRevolvingCreditFacilityMember
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Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
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- Details

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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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- Details

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Debt and Financing Arrangements - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended				9 Months Ended
	Jul. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Apr. 30, 2020
Debt Instrument [Line Items]
Gain (Loss) on Extinguishment of Debt		$ 0			$ 60	$ 0	$ 60
$500 million due March 2020 [Member]
Debt Instrument [Line Items]
Repayments of Debt			$ 500
Debt Instrument, Interest Rate, Stated Percentage			5.00%
$2.5 billion facility expiring Dec 2024 [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 2,500
$500 million facility expiring Dec 2020 [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				500
$2 billion committed revolving credit facility [Member]
Debt Instrument [Line Items]
Line of Credit, Borrowing Capacity, Terminated				$ 2,000
Debt Instrument, Term				5 years
$750 million total capacity revolving credit facilities [Member]
Debt Instrument [Line Items]
Line of Credit, Borrowing Capacity, Terminated				$ 750
Debt Instrument, Term				364 days
Bank term loans due April 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount								$ 575
European financing arrangements due Sept 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount								$ 675
Subsequent Event [Member]
Debt Instrument [Line Items]
Bank term loans outstanding	$ 275
Subsequent Event [Member] \| $300 million bank term loan [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 300