TIFSA Condensed Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 412	$ 579	$ 292	$ 553
Accounts receivable - net	6,094	6,394
Inventories	3,138	2,888
Intercompany receivables	0	0
Assets held for sale	2,037	5,812
Other current assets	1,548	1,436
Current assets	13,229	17,109
Property, plant and equipment - net	5,601	5,632
Goodwill	19,644	21,024
Other intangible assets - net	6,687	7,540
Investments in partially-owned affiliates	1,099	990
Investments in affiliates	0	0
Intercompany loans receivable	0	0
Noncurrent assets held for sale	0	7,374
Other noncurrent assets	3,347	3,510
Total assets	49,607	63,179
Short-term debt	1,124	1,078
Current portion of long-term debt	542	628
Accounts payable	3,720	4,000
Accrued compensation and benefits	1,082	1,333
Liabilities held for sale	237	4,276
Intercompany payables	0	0
Other current liabilities	4,037	5,016
Current liabilities	10,742	16,331
Long-term debt	11,810	11,053
Pension and postretirement benefits	1,048	1,550
Intercompany loans payable	0	0
Noncurrent liabilities held for sale	0	3,888
Other noncurrent liabilities	5,638	5,033
Long-term liabilities	18,496	21,524
Redeemable noncontrolling interests	168	234
Ordinary shares	9	9
Ordinary shares held in treasury	(172)	(20)
Other shareholders' equity	19,551	24,129
Shareholders' equity attributable to Johnson Controls	19,388	24,118
Nonredeemable noncontrolling interest	813	972
Total equity	20,201	25,090
Total liabilities, redeemable noncontrolling interest and equity	49,607	63,179
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	(361)	0
Accounts receivable - net	0	0
Inventories	0	0
Intercompany receivables	(8,800)	(6,206)
Assets held for sale	0	0
Other current assets	0	0
Current assets	(9,161)	(6,206)
Property, plant and equipment - net	0	0
Goodwill	0	0
Other intangible assets - net	0	0
Investments in partially-owned affiliates	0	0
Investments in affiliates	(67,995)	(71,245)
Intercompany loans receivable	(33,579)	(47,647)
Noncurrent assets held for sale		0
Other noncurrent assets	0	0
Total assets	(110,735)	(125,098)
Short-term debt	(361)	0
Current portion of long-term debt	0	0
Accounts payable	0	0
Accrued compensation and benefits	0	0
Liabilities held for sale	0	0
Intercompany payables	(8,800)	(6,206)
Other current liabilities	0	0
Current liabilities	(9,161)	(6,206)
Long-term debt	0	0
Pension and postretirement benefits	0	0
Intercompany loans payable	(33,579)	(47,647)
Noncurrent liabilities held for sale		0
Other noncurrent liabilities	0	0
Long-term liabilities	(33,579)	(47,647)
Redeemable noncontrolling interests	0	0
Ordinary shares	0	0
Ordinary shares held in treasury	0	0
Other shareholders' equity	(67,995)	(71,245)
Shareholders' equity attributable to Johnson Controls	(67,995)	(71,245)
Nonredeemable noncontrolling interest	0	0
Total equity	(67,995)	(71,245)
Total liabilities, redeemable noncontrolling interest and equity	(110,735)	(125,098)
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	3	11
Accounts receivable - net	0	0
Inventories	0	0
Intercompany receivables	1,803	16
Assets held for sale	0	0
Other current assets	14	6
Current assets	1,820	33
Property, plant and equipment - net	0	0
Goodwill	243	0
Other intangible assets - net	0	0
Investments in partially-owned affiliates	0	0
Investments in affiliates	17,112	12,460
Intercompany loans receivable	18,205	18,680
Noncurrent assets held for sale		0
Other noncurrent assets	0	0
Total assets	37,380	31,173
Short-term debt	885	0
Current portion of long-term debt	444	0
Accounts payable	1	1
Accrued compensation and benefits	0	0
Liabilities held for sale	0	0
Intercompany payables	2,588	3,873
Other current liabilities	292	3
Current liabilities	4,210	3,877
Long-term debt	7,347	0
Pension and postretirement benefits	0	0
Intercompany loans payable	6,435	3,178
Noncurrent liabilities held for sale		0
Other noncurrent liabilities	0	0
Long-term liabilities	13,782	3,178
Redeemable noncontrolling interests	0	0
Ordinary shares	9	9
Ordinary shares held in treasury	(172)	(20)
Other shareholders' equity	19,551	24,129
Shareholders' equity attributable to Johnson Controls	19,388	24,118
Nonredeemable noncontrolling interest	0	0
Total equity	19,388	24,118
Total liabilities, redeemable noncontrolling interest and equity	37,380	31,173
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0
Accounts receivable - net	0	0
Inventories	0	0
Intercompany receivables	2,039	0
Assets held for sale	0	0
Other current assets	0	0
Current assets	2,039	0
Property, plant and equipment - net	0	0
Goodwill	0	0
Other intangible assets - net	0	0
Investments in partially-owned affiliates	0	0
Investments in affiliates	28,629	31,142
Intercompany loans receivable	4,140	0
Noncurrent assets held for sale		0
Other noncurrent assets	0	0
Total assets	34,808	31,142
Short-term debt	76	0
Current portion of long-term debt	0	0
Accounts payable	0	0
Accrued compensation and benefits	0	0
Liabilities held for sale	0	0
Intercompany payables	1,007	0
Other current liabilities	2	2
Current liabilities	1,085	2
Long-term debt	0	0
Pension and postretirement benefits	0	0
Intercompany loans payable	18,205	18,680
Noncurrent liabilities held for sale		0
Other noncurrent liabilities	0	0
Long-term liabilities	18,205	18,680
Redeemable noncontrolling interests	0	0
Ordinary shares	0	0
Ordinary shares held in treasury	0	0
Other shareholders' equity	15,518	12,460
Shareholders' equity attributable to Johnson Controls	15,518	12,460
Nonredeemable noncontrolling interest	0	0
Total equity	15,518	12,460
Total liabilities, redeemable noncontrolling interest and equity	34,808	31,142
Subsidiary Issuer [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	288	244
Accounts receivable - net	0	0
Inventories	0	0
Intercompany receivables	382	2
Assets held for sale	0	0
Other current assets	1	1
Current assets	671	247
Property, plant and equipment - net	0	0
Goodwill	32	274
Other intangible assets - net	0	0
Investments in partially-owned affiliates	0	0
Investments in affiliates	22,254	27,643
Intercompany loans receivable	2,836	13,336
Noncurrent assets held for sale		0
Other noncurrent assets	18	0
Total assets	25,811	41,500
Short-term debt	0	0
Current portion of long-term debt	18	0
Accounts payable	0	0
Accrued compensation and benefits	0	0
Liabilities held for sale	0	0
Intercompany payables	4,343	2,315
Other current liabilities	23	32
Current liabilities	4,384	2,347
Long-term debt	149	2,413
Pension and postretirement benefits	0	0
Intercompany loans payable	1,964	12,453
Noncurrent liabilities held for sale		0
Other noncurrent liabilities	24	22
Long-term liabilities	2,137	14,888
Redeemable noncontrolling interests	0	0
Ordinary shares	0	0
Ordinary shares held in treasury	0	0
Other shareholders' equity	19,290	24,265
Shareholders' equity attributable to Johnson Controls	19,290	24,265
Nonredeemable noncontrolling interest	0	0
Total equity	19,290	24,265
Total liabilities, redeemable noncontrolling interest and equity	25,811	41,500
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	482	324
Accounts receivable - net	6,094	6,394
Inventories	3,138	2,888
Intercompany receivables	4,576	6,188
Assets held for sale	2,037	5,812
Other current assets	1,533	1,429
Current assets	17,860	23,035
Property, plant and equipment - net	5,601	5,632
Goodwill	19,369	20,750
Other intangible assets - net	6,687	7,540
Investments in partially-owned affiliates	1,099	990
Investments in affiliates	0	0
Intercompany loans receivable	8,398	15,631
Noncurrent assets held for sale		7,374
Other noncurrent assets	3,329	3,510
Total assets	62,343	84,462
Short-term debt	524	1,078
Current portion of long-term debt	80	628
Accounts payable	3,719	3,999
Accrued compensation and benefits	1,082	1,333
Liabilities held for sale	237	4,276
Intercompany payables	862	18
Other current liabilities	3,720	4,979
Current liabilities	10,224	16,311
Long-term debt	4,314	8,640
Pension and postretirement benefits	1,048	1,550
Intercompany loans payable	6,975	13,336
Noncurrent liabilities held for sale		3,888
Other noncurrent liabilities	5,614	5,011
Long-term liabilities	17,951	32,425
Redeemable noncontrolling interests	168	234
Ordinary shares	0	0
Ordinary shares held in treasury	0	0
Other shareholders' equity	33,187	34,520
Shareholders' equity attributable to Johnson Controls	33,187	34,520
Nonredeemable noncontrolling interest	813	972
Total equity	34,000	35,492
Total liabilities, redeemable noncontrolling interest and equity	$ 62,343	$ 84,462