TIFSA Condensed Statement of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Statement of Income Captions [Line Items]
Net income (loss)	$ 629	$ 459	$ 892	$ 480
Foreign currency translation adjustments	285	(141)	(166)	(115)
Realized and unrealized gains (losses) on derivatives	(9)	4	(13)	6
Realized and unrealized gains (losses) on marketable securities	(3)	0	6	0
Other comprehensive income (loss)	273	(137)	(173)	(109)
Total comprehensive income (loss)	902	322	719	371
Comprehensive income attributable to noncontrolling interests	89	74	140	185
Comprehensive income (loss) attributable to Johnson Controls	813	248	579	186
Consolidation, Eliminations [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss)	(1,162)		559
Foreign currency translation adjustments	(268)		150
Realized and unrealized gains (losses) on derivatives	7		13
Realized and unrealized gains (losses) on marketable securities	3		(6)
Other comprehensive income (loss)	(258)		157
Total comprehensive income (loss)	(1,420)		716
Comprehensive income attributable to noncontrolling interests	0		0
Comprehensive income (loss) attributable to Johnson Controls	(1,420)		716
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss)	555		736
Foreign currency translation adjustments	268		(150)
Realized and unrealized gains (losses) on derivatives	(7)		(13)
Realized and unrealized gains (losses) on marketable securities	(3)		6
Other comprehensive income (loss)	258		(157)
Total comprehensive income (loss)	813		579
Comprehensive income attributable to noncontrolling interests	0		0
Comprehensive income (loss) attributable to Johnson Controls	813		579
Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss)	556		129
Foreign currency translation adjustments	(30)		(37)
Realized and unrealized gains (losses) on derivatives	0		0
Realized and unrealized gains (losses) on marketable securities	0		0
Other comprehensive income (loss)	(30)		(37)
Total comprehensive income (loss)	526		92
Comprehensive income attributable to noncontrolling interests	0		0
Comprehensive income (loss) attributable to Johnson Controls	526		92
Subsidiary Issuer [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss)	60		(1,353)
Foreign currency translation adjustments	(4)		22
Realized and unrealized gains (losses) on derivatives	0		0
Realized and unrealized gains (losses) on marketable securities	(6)		1
Other comprehensive income (loss)	(10)		23
Total comprehensive income (loss)	50		(1,330)
Comprehensive income attributable to noncontrolling interests	0		0
Comprehensive income (loss) attributable to Johnson Controls	50		(1,330)
Non-Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss)	620		821
Foreign currency translation adjustments	319		(151)
Realized and unrealized gains (losses) on derivatives	(9)		(13)
Realized and unrealized gains (losses) on marketable securities	3		5
Other comprehensive income (loss)	313		(159)
Total comprehensive income (loss)	933		662
Comprehensive income attributable to noncontrolling interests	89		140
Comprehensive income (loss) attributable to Johnson Controls	844		522
Parent [Member]
Condensed Statement of Income Captions [Line Items]
Foreign currency translation adjustments		(141)		(126)
Realized and unrealized gains (losses) on derivatives		6		9
Realized and unrealized gains (losses) on marketable securities		0		0
Comprehensive income (loss) attributable to Johnson Controls	$ 813	$ 248	$ 579	$ 186