Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 236	$ 558	$ 427	$ 957
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	(494)	117	(233)	(1)
Realized and unrealized gains (losses) on derivatives	(10)	17	(3)	19
Pension and postretirement plans	0	0	(1)	0
Other comprehensive income (loss)	(504)	134	(237)	18
Total comprehensive income (loss)	(268)	692	190	975
Comprehensive income attributable to noncontrolling interests	0	49	44	103
Comprehensive income (loss) attributable to Johnson Controls	$ (268)	$ 643	$ 146	$ 872

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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