Consolidated Statements of Shareholders' Equity Attributable to Johnson Controls Ordinary Shareholders Consolidated Statements of Shareholders' Equity Attributable to Johnson Controls Ordinary Shareholders - USD ($) $ in Millions	Total	Ordinary Shares	Capital in excess of par value	Retained Earnings	Treasury Stock, at Cost	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Sep. 30, 2017	$ 20,447	$ 9	$ 16,390	$ 5,231	$ (710)	$ (473)
Comprehensive income (loss) attributable to Johnson Controls	289	0	0	230	0	59
Cash dividends - ordinary shares	(242)	0	0	(242)	0	0
Repurchase of ordinary shares	(150)	0	0	0	(150)	0
Accounting Pronouncement | Adoption of ASU 2016-09	179	0	0	179	0	0
Accounting Pronouncement | Adoption of ASU 2016-01						0
Other, including options exercised	12	0	37	0	(25)	0
Ending balance at Dec. 31, 2017	20,535	9	16,427	5,398	(885)	(414)
Beginning balance at Sep. 30, 2018	21,164	10	16,549	6,604	(1,053)	(946)
Comprehensive income (loss) attributable to Johnson Controls	229	0	0	355	0	(126)
Cash dividends - ordinary shares	(240)	0	0	(240)	0	0
Repurchase of ordinary shares	(467)	0	0	0	(467)	0
Accounting Pronouncement | Adoption of ASC 606	(45)	0	0	(45)	0	0
Accounting Pronouncement | Adoption of ASU 2016-01	0	0	0	8	0	(8)
Accounting Pronouncement | Adoption of ASU 2016-16	(546)	0	0	(546)	0	0
Other, including options exercised	7	0	30	0	(23)	0
Ending balance at Dec. 31, 2018	$ 20,102	$ 10	$ 16,579	$ 6,136	$ (1,543)	$ (1,080)