Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities of Continuing Operations
Net income from continuing operations attributable to Johnson Controls	$ 1,244	$ 190
Income from continuing operations attributable to noncontrolling interests	186	115
Income from continuing operations	1,430	305
Adjustments to reconcile net income from continuing operations to cash provided by operating activities:
Depreciation and amortization	627	616
Pension and postretirement benefit income	(393)	42
Pension and postretirement contributions	(40)	(43)
Equity in earnings of partially-owned affiliates, net of dividends received	(66)	9
Deferred income taxes	6	(148)
Non-cash restructuring and impairment charges	94	582
Equity-based compensation	51	61
Other - net	(89)	(38)
Changes in assets and liabilities, excluding acquisitions and divestitures:
Accounts receivable	(157)	428
Inventories	(204)	(205)
Other assets	(30)	(120)
Restructuring reserves	(27)	58
Accounts payable and accrued liabilities	854	(731)
Accrued income taxes	(34)	683
Cash provided by operating activities from continuing operations	2,022	1,499
Investing Activities of Continuing Operations
Capital expenditures	(324)	(347)
Sale of property, plant and equipment	76	98
Acquisition of businesses, net of cash acquired	(707)	(59)
Business divestitures, net of cash divested	19	0
Proceeds from equity swap	35	0
Changes in long-term investments	14	(1)
Payments for (Proceeds from) Other Investing Activities	1	0
Cash used by investing activities	(886)	(309)
Financing Activities of Continuing Operations
Increase in short-term debt - net	239	1,312
Repayment of long-term debt	(303)	(505)
Debt financing costs	0	(4)
Stock repurchases and retirements	(1,001)	(1,467)
Payment of cash dividends	(570)	(596)
Proceeds from the exercise of stock options	160	42
Employee equity-based compensation withholding taxes	(30)	(33)
Change in noncontrolling interest share	(14)	0
Dividends paid to noncontrolling interests	(133)	(67)
Proceeds for previous acquisitions and divestitures	2	2
Cash used by financing activities from continuing operations	(1,650)	(1,316)
Discontinued Operations
Cash Used by Operating Activities, Discontinued Operations	(56)	(255)
Cash Used by Financing Activities, Discontinued Operations	0	(113)
Net Cash Used by Discontinued Operations	(56)	(368)
Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations	67	28
Decrease in Cash, Cash Equivalents and Restricted Cash	(503)	(466)
Cash, cash equivalents and restricted cash at beginning of period	1,960	2,821
Cash, cash equivalents and restricted cash at end of period	1,457	2,355
Less: Restricted Cash	7	13
Cash and cash equivalents at end of period	$ 1,450	$ 2,342