Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 5,887	$ 2,383	$ 1,819
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(342)	(483)	103
Realized and unrealized gains (losses) on derivatives	6	(29)	(14)
Realized and unrealized gains on marketable securities	0	4	5
Pension and postretirement plans	(6)	0	0
Other comprehensive income (loss)	(342)	(508)	94
Total comprehensive income	5,545	1,875	1,913
Comprehensive income attributable to noncontrolling interests	195	186	203
Comprehensive income attributable to Johnson Controls	$ 5,350	$ 1,689	$ 1,710

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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