Equity and Noncontrolling Interests Equity Attributable to Johnson Controls, Inc. and Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Equity [Line Items]
Stock Repurchase Program, Authorized Amount	$ 3,650
Payments for Repurchase of Common Stock	501	$ 1,362	$ 1,249
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	10,335	11,270	12,273
Beginning balance	163
Beginning balance	10,498
Net income attributable to Johnson Controls, Inc.	(847)	1,563	1,215
Foreign currency translation adjustments	(28)	(825)	(642)
Realized and unrealized gains (losses) on marketable common stock	(1)	0	(7)
Pension and postretirement plans	(1)	(10)	(5)
Other comprehensive loss	(21)	(845)	(657)
Comprehensive income (loss) attributable to Johnson Controls, Inc.	(877)	743	560
Comprehensive income attributable to noncontrolling interest	224	91	126
Total Comprehensive income (loss)	(653)	834	686
Cash dividends - common stock	(752)	(681)	586
Repurchases of common stock	(501)	(1,362)	(1,249)
Stockholders Equity, Change due to Merger	(6,500)
Other, including options exercised	(157)	(365)	(272)
Ending balance	1,862	10,335	11,270
Ending balance	938	163
Ending balance	2,800	10,498
Parent
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	10,335	11,270	12,273
Net income attributable to Johnson Controls, Inc.	(847)	1,563	1,215
Foreign currency translation adjustments	(39)	(799)	(640)
Realized and unrealized gains (losses) on derivatives	11	(11)	(3)
Realized and unrealized gains (losses) on marketable common stock	(1)		(7)
Pension and postretirement plans	(1)	(10)	(5)
Other comprehensive loss	(30)	(820)	(655)
Comprehensive income (loss) attributable to Johnson Controls, Inc.	(877)	743	560
Cash dividends - common stock	(752)	(681)	(586)
Dividends attributable to noncontrolling interests	0	0	0
Repurchases of common stock	(501)	(1,362)	(1,249)
Stockholders Equity, Change due to Merger	(6,500)
Change in noncontrolling interest share	0	0	0
Other, including options exercised	(157)	(365)	(272)
Ending balance	1,862	10,335	11,270
Nonredeemable Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	163	251	260
Income from continuing operations attributable to noncontrolling interests	167	65	90
Foreign currency translation adjustments	9	(3)	(2)
Realized and unrealized gains (losses) on derivatives	(1)	0	0
Realized and unrealized gains (losses) on marketable common stock	0		0
Pension and postretirement plans	0	0	0
Other comprehensive loss	8	(3)	(2)
Comprehensive income attributable to noncontrolling interest	175	62	88
Cash dividends - common stock	0	0	0
Dividends attributable to noncontrolling interests	(92)	(57)	(59)
Repurchases of common stock	0	0	0
Stockholders Equity, Change due to Merger	0
Change in noncontrolling interest share	692	(93)	(32)
Other, including options exercised	0	0	6
Ending balance	938	163	251
Stockholders' Equity, Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	10,498	11,521	12,533
Net Income	(680)	1,628	1,305
Foreign currency translation adjustments	(30)	(802)	(642)
Realized and unrealized gains (losses) on derivatives	10	(11)	(3)
Realized and unrealized gains (losses) on marketable common stock	(1)		(7)
Pension and postretirement plans	(1)	(10)	(5)
Other comprehensive loss	(22)	(823)	(657)
Total Comprehensive income (loss)	(702)	805	648
Cash dividends - common stock	(752)	(681)	(586)
Dividends attributable to noncontrolling interests	(92)	(57)	(59)
Repurchases of common stock	(501)	(1,362)	(1,249)
Stockholders Equity, Change due to Merger	(6,500)
Change in noncontrolling interest share	692	(93)	(32)
Other, including options exercised	(157)	(365)	(266)
Ending balance	$ 2,800	$ 10,498	$ 11,521