Summary of Significant Accounting Policies Narrative (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended													12 Months Ended		3 Months Ended			12 Months Ended
	Dec. 31, 2011 InterestInvestment	Sep. 30, 2013 Segment Entity	Sep. 30, 2012 Entity	Sep. 30, 2011	Sep. 30, 2013 Minimum	Sep. 30, 2013 Maximum	Sep. 30, 2013 Building And Improvements Minimum	Sep. 30, 2013 Building And Improvements Maximum	Sep. 30, 2013 Machinery and Equipment Minimum	Sep. 30, 2013 Machinery and Equipment Maximum	Sep. 30, 2013 Nonconsolidated VIEs 2	Sep. 30, 2012 Nonconsolidated VIEs 2	Sep. 30, 2013 Nonconsolidated VIEs 1	Sep. 30, 2012 Nonconsolidated VIEs 1	Sep. 30, 2013 Power Solutions Entity	Sep. 30, 2013 Automotive Experience North America Entity	Jun. 30, 2013 Effect Of Change [Member]	Mar. 31, 2013 Effect Of Change [Member]	Dec. 31, 2012 Effect Of Change [Member]	Sep. 30, 2013 Effect Of Change [Member]	Sep. 30, 2012 Effect Of Change [Member]	Sep. 30, 2011 Effect Of Change [Member]	Sep. 30, 2013 After Reorganization Automotive Experience Segment	Sep. 30, 2013 Par Value Before Simplification	Oct. 30, 2013 Subsequent Event
Financial Statement Details [Line Items]
Interest percentage minimum for investments in partially-owned affiliates to be accounted for by the equity method		20.00%
Number of VIEs in which Company was primary beneficiary		3	3												1	2
Number of separate investments a pre-existing VIE was reorganized into	3
Number of reorganized investments in which the Company acquired additional interests	2
Third party debt agreement		$ 175
Loans to partially-owned affiliates		64
Floor guarantee		25
Interest percentage acquired in equity method investee		40.00%
Remaining equity interest percentage that may be acquired in equity method investee		60.00%
Number of months after the fifth anniversary of the closing date that the Company is subject to a contractual obligation at the counterparty's option to sell the Company's equity investment in the investee to the counterparty		6 months
Investment balance of the Company's nonconsolidated VIEs											56	55	57	52
Percentage of interest acquired				49.00%																					50.00%
Total ownership percentage				100.00%																					90.00%
Number of VIEs in which Company was not primary beneficiary		2
Maturity period to be considered cash equivalents		Three months or less
Restricted cash and cash equivalents		32	29
Net income attributable to Johnson Controls, Inc.		1,178	1,184	1,415													(21)	16	5	7	(42)	0
Diluted		$ 1.71	$ 1.72	$ 2.06													$ (0.03)	$ 0.03	$ 0.01	$ 0.01	$ (0.06)	$ 0.00
Engineering and research and development costs to be reimbursed		259	382
Expected reimbursement period of less than one year		Less than one year
Expected reimbursement period beyond one year		Beyond one year
Molds, dies and other tools costs capitalized within property, plant and equipment		99	113
Molds, dies and other tools costs to be reimbursed		297	284
Estimated useful lives							3 years	40 years	3 years	15 years
Costs and earnings in excess of billings related to contracts		489	531
Billing in excess of costs and earnings on uncompleted contracts		263	321
Timing of the first deliverable to the last delivery		Approximately four to twelve months
Duration of extended warranty arrangements		One to five years commencing upon the end of the standard warranty period			1 year	5 years
Research activities costs relating to product development and improvement, net of customer reimbursements		1,006	1,025	876
Customer reimbursements included in research activities costs		448	516	366
Foreign currency transaction gains (losses)		$ (25)	$ 12	$ (22)
Number of reportable segments		9																					3
Common stock, par value		$ 1.00	$ 1.00																					$ 0.0139