Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 174	$ 52	$ 330	$ 471
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	10	(16)	100	70
Realized and unrealized gains on derivatives	20	10	3	17
Pension and postretirement plans	0	(1)	(1)	(2)
Other comprehensive income (loss)	30	(7)	102	85
Total comprehensive income	204	45	432	556
Comprehensive income attributable to noncontrolling interests:
Net income	41	41	79	79
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	11	(10)	42	(8)
Realized and unrealized gains (losses) on derivatives	1	1	(5)	4
Other comprehensive income (loss)	12	(9)	37	(4)
Comprehensive income attributable to noncontrolling interests	53	32	116	75
Comprehensive income attributable to Johnson Controls	$ 151	$ 13	$ 316	$ 481