Nonconsolidated Partially-Owned Affiliates (Detail)	12 Months Ended
Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Percentage of results of operations	100.00%

Percentage Of Consolidated Operating Results Of Non Consolidated Partially Owned Affiliates

No definition available.

Name:	jci_PercentageOfConsolidatedOperatingResultsOfNonConsolidatedPartiallyOwnedAffiliates
Namespace Prefix:	jci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration