Equity and Noncontrolling Interests - Equity Attributable to Johnson Controls, Inc. and Noncontrolling Interests (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Equity [Line Items]
Noncontrolling interest acquired	$ 691		$ 691
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			10,376
Beginning balance			163
Beginning balance			10,539
Net income attributable to Johnson Controls, Inc.	383	$ 178	303	$ 1,214
Foreign currency translation adjustments	(141)	147	(115)	(708)
Realized and unrealized gains (losses) on derivatives	4	(1)	6	(4)
Pension and postretirement plans	0	0	0	(3)
Other comprehensive income (loss)	(137)	146	(109)	(715)
Comprehensive income attributable to Johnson Controls, Inc.	248	319	186	516
Comprehensive income attributable to noncontrolling interests	74	34	185	79
Total comprehensive income	322	353	371	595
Ending balance	9,599	10,655	9,599	10,655
Ending balance	924	185	924	185
Ending balance	10,523	10,840	10,523	10,840
Equity Attributable to Johnson Controls, Inc
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	9,984	10,583	10,376	11,311
Net income attributable to Johnson Controls, Inc.	383	178	303	1,214
Foreign currency translation adjustments	(141)	144	(126)	(688)
Realized and unrealized gains (losses) on derivatives	6	(3)	9	(7)
Pension and postretirement plans			0	(3)
Other comprehensive income (loss)	(135)	141	(117)	(698)
Comprehensive income attributable to Johnson Controls, Inc.	248	319	186	516
Cash dividends - common stock	(189)	(171)	(566)	(513)
Dividends attributable to noncontrolling interests	0	0	0	0
Repurchases of common stock	(475)	(190)	(475)	(1,000)
Change In Noncontrolling Interest Share	0	0	0	0
Other, including options exercised	31	114	78	341
Ending balance	9,599	10,655	9,599	10,655
Equity Attributable to Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	898	199	163	251
Income attributable to noncontrolling interests	59	17	129	53
Foreign currency translation adjustments	3	(1)	12	(4)
Realized and unrealized gains (losses) on derivatives	(2)	0	(1)	0
Pension and postretirement plans			0	0
Other comprehensive income (loss)	1	(1)	11	(4)
Comprehensive income attributable to noncontrolling interests	60	16	140	49
Cash dividends - common stock	0	0	0	0
Dividends attributable to noncontrolling interests	(35)	(23)	(71)	(39)
Repurchases of common stock	0	0	0	0
Change In Noncontrolling Interest Share	1	(7)	692	(76)
Other, including options exercised	0	0	0	0
Ending balance	924	185	924	185
Total Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	10,882	10,782	10,539	11,562
Net income	442	195	432	1,267
Foreign currency translation adjustments	(138)	143	(114)	(692)
Realized and unrealized gains (losses) on derivatives	4	(3)	8	(7)
Pension and postretirement plans			0	(3)
Other comprehensive income (loss)	(134)	140	(106)	(702)
Total comprehensive income	308	335	326	565
Cash dividends - common stock	(189)	(171)	(566)	(513)
Dividends attributable to noncontrolling interests	(35)	(23)	(71)	(39)
Repurchases of common stock	(475)	(190)	(475)	(1,000)
Change In Noncontrolling Interest Share	1	(7)	692	(76)
Other, including options exercised	31	114	78	341
Ending balance	$ 10,523	$ 10,840	$ 10,523	$ 10,840