Cover	6 Months Ended
	Mar. 31, 2023 shares
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-13836
Entity Registrant Name	JOHNSON CONTROLS INTERNATIONAL PLC
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	98-0390500
Entity Address, Address Line One	One Albert Quay
Entity Address, City or Town	Cork
Entity Address, Country	IE
Entity Address, Postal Zip Code	T12 X8N6
City Area Code	353
Local Phone Number	21-423-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	686,098,829
Entity Central Index Key	0000833444
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false
Ordinary Shares, Par Value $0.01
Document Information [Line Items]
Title of 12(b) Security	Ordinary Shares, Par Value $0.01
Trading Symbol	JCI
Security Exchange Name	NYSE
1.000% Senior Notes due 2023
Document Information [Line Items]
Title of 12(b) Security	1.000% Senior Notes due 2023
Trading Symbol	JCI23A
Security Exchange Name	NYSE
3.625% Senior Notes due 2024
Document Information [Line Items]
Title of 12(b) Security	3.625% Senior Notes due 2024
Trading Symbol	JCI24A
Security Exchange Name	NYSE
1.375% Notes due 2025
Document Information [Line Items]
Title of 12(b) Security	1.375% Notes due 2025
Trading Symbol	JCI25A
Security Exchange Name	NYSE
3.900% Notes due 2026
Document Information [Line Items]
Title of 12(b) Security	3.900% Notes due 2026
Trading Symbol	JCI26A
Security Exchange Name	NYSE
0.375% Senior Notes due 2027
Document Information [Line Items]
Title of 12(b) Security	0.375% Senior Notes due 2027
Trading Symbol	JCI27
Security Exchange Name	NYSE
3.000% Senior Notes due 2028
Document Information [Line Items]
Title of 12(b) Security	3.000% Senior Notes due 2028
Trading Symbol	JCI28
Security Exchange Name	NYSE
1.750% Senior Notes due 2030
Document Information [Line Items]
Title of 12(b) Security	1.750% Senior Notes due 2030
Trading Symbol	JCI30
Security Exchange Name	NYSE
2.000% Sustainability-Linked Senior Notes due 2031
Document Information [Line Items]
Title of 12(b) Security	2.000% Sustainability-Linked Senior Notes due 2031
Trading Symbol	JCI31
Security Exchange Name	NYSE
1.000% Senior Notes due 2032
Document Information [Line Items]
Title of 12(b) Security	1.000% Senior Notes due 2032
Trading Symbol	JCI32
Security Exchange Name	NYSE
4.900% Senior Notes due 2032
Document Information [Line Items]
Title of 12(b) Security	4.900% Senior Notes due 2032
Trading Symbol	JCI32A
Security Exchange Name	NYSE
6.000% Notes due 2036
Document Information [Line Items]
Title of 12(b) Security	6.000% Notes due 2036
Trading Symbol	JCI36A
Security Exchange Name	NYSE
5.70% Senior Notes due 2041
Document Information [Line Items]
Title of 12(b) Security	5.70% Senior Notes due 2041
Trading Symbol	JCI41B
Security Exchange Name	NYSE
5.250% Senior Notes due 2041
Document Information [Line Items]
Title of 12(b) Security	5.250% Senior Notes due 2041
Trading Symbol	JCI41C
Security Exchange Name	NYSE
4.625% Senior Notes due 2044
Document Information [Line Items]
Title of 12(b) Security	4.625% Senior Notes due 2044
Trading Symbol	JCI44A
Security Exchange Name	NYSE
5.125% Notes due 2045
Document Information [Line Items]
Title of 12(b) Security	5.125% Notes due 2045
Trading Symbol	JCI45B
Security Exchange Name	NYSE
6.950% Debentures due December 1, 2045
Document Information [Line Items]
Title of 12(b) Security	6.950% Debentures due December 1, 2045
Trading Symbol	JCI45A
Security Exchange Name	NYSE
4.500% Senior Notes due 2047
Document Information [Line Items]
Title of 12(b) Security	4.500% Senior Notes due 2047
Trading Symbol	JCI47
Security Exchange Name	NYSE
4.950% Senior Notes due 2064
Document Information [Line Items]
Title of 12(b) Security	4.950% Senior Notes due 2064
Trading Symbol	JCI64A
Security Exchange Name	NYSE