TIFSA Condensed Income Statement (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Condensed Income Statements, Captions [Line Items]
Net sales	$ 7,267		$ 4,733	$ 14,353	$ 9,429
Cost of sales	4,986		3,446	9,958	6,885
Gross profit	2,281		1,287	4,395	2,544
Selling, general and administrative expenses	(1,726)		(899)	(3,296)	(1,746)
Restructuring and impairment costs	(99)	$ (78)	(60)	(177)	(60)
Net Financing Charges	(116)		(71)	(252)	(137)
Equity income (loss)	53		40	108	82
Intercompany interest and fees	0			0
Income (loss) from continuing operations before income taxes	393		297	778	683
Income tax provision	508		41	481	124
Income (loss) from continuing operations	(115)		256	297	559
Income (loss) from sale of intercompany investment, net of tax				0
Loss from discontinued operations, net of tax	0		(725)	(34)	(538)
Net income (loss)	(115)		(469)	263	21
Income from continuing operations attributable to noncontrolling interests	33		38	73	61
Income from discontinued operations attributable to noncontrolling interests	0		23	9	40
Net income (loss) attributable to Johnson Controls	(148)		$ (530)	181	$ (80)
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	0			0
Cost of sales	0			0
Gross profit	0			0
Selling, general and administrative expenses	0			0
Restructuring and impairment costs	0			0
Net Financing Charges	0			0
Equity income (loss)	709			786
Intercompany interest and fees	0			0
Income (loss) from continuing operations before income taxes	709			786
Income tax provision	0			0
Income (loss) from continuing operations				786
Income (loss) from sale of intercompany investment, net of tax				935
Loss from discontinued operations, net of tax				0
Net income (loss)	709			1,721
Income from continuing operations attributable to noncontrolling interests	0			0
Income from discontinued operations attributable to noncontrolling interests				0
Net income (loss) attributable to Johnson Controls	709			1,721
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	0			0
Cost of sales	0			0
Gross profit	0			0
Selling, general and administrative expenses	(4)			(6)
Restructuring and impairment costs	0			0
Net Financing Charges	(59)			(78)
Equity income (loss)	(103)			215
Intercompany interest and fees	18			50
Income (loss) from continuing operations before income taxes	(148)			181
Income tax provision	0			0
Income (loss) from continuing operations				181
Income (loss) from sale of intercompany investment, net of tax				0
Loss from discontinued operations, net of tax				0
Net income (loss)	(148)			181
Income from continuing operations attributable to noncontrolling interests	0			0
Income from discontinued operations attributable to noncontrolling interests				0
Net income (loss) attributable to Johnson Controls	(148)			181
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	0			0
Cost of sales	0			0
Gross profit	0			0
Selling, general and administrative expenses	0			0
Restructuring and impairment costs	0			0
Net Financing Charges	0			0
Equity income (loss)	(201)			(500)
Intercompany interest and fees	73			73
Income (loss) from continuing operations before income taxes	(128)			(427)
Income tax provision	0			0
Income (loss) from continuing operations				(427)
Income (loss) from sale of intercompany investment, net of tax				0
Loss from discontinued operations, net of tax				0
Net income (loss)	(128)			(427)
Income from continuing operations attributable to noncontrolling interests	0			0
Income from discontinued operations attributable to noncontrolling interests				0
Net income (loss) attributable to Johnson Controls	(128)			(427)
Subsidiary Issuer [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	0			0
Cost of sales				0
Gross profit	0			0
Selling, general and administrative expenses	(1)			0
Restructuring and impairment costs	0			0
Net Financing Charges	5			(14)
Equity income (loss)	(405)			(501)
Intercompany interest and fees	20			37
Income (loss) from continuing operations before income taxes	(381)			(478)
Income tax provision	0			0
Income (loss) from continuing operations				(478)
Income (loss) from sale of intercompany investment, net of tax				(935)
Loss from discontinued operations, net of tax				0
Net income (loss)	(381)			(1,413)
Income from continuing operations attributable to noncontrolling interests	0			0
Income from discontinued operations attributable to noncontrolling interests				0
Net income (loss) attributable to Johnson Controls	(381)			(1,413)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	7,267			14,353
Cost of sales	4,986			9,958
Gross profit	2,281			4,395
Selling, general and administrative expenses	(1,721)			(3,290)
Restructuring and impairment costs	(99)			(177)
Net Financing Charges	(62)			(160)
Equity income (loss)	53			108
Intercompany interest and fees	(111)			(160)
Income (loss) from continuing operations before income taxes	341			716
Income tax provision	508			481
Income (loss) from continuing operations				235
Income (loss) from sale of intercompany investment, net of tax				0
Loss from discontinued operations, net of tax				(34)
Net income (loss)	(167)			201
Income from continuing operations attributable to noncontrolling interests	33			73
Income from discontinued operations attributable to noncontrolling interests				9
Net income (loss) attributable to Johnson Controls	$ (200)			$ 119