Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income attributable to Johnson Controls	$ 668	$ 181
Income from continuing operations attributable to noncontrolling interests	86	73
Income from discontinued operations attributable to noncontrolling interests	0	9
Net income	754	263
Adjustments to reconcile net income to cash provided (used) by operating activities:
Depreciation and amortization	552	638
Pension and postretirement benefit income	(72)	(202)
Pension and postretirement contributions	(37)	(258)
Equity in earnings of partially-owned affiliates, net of dividends received	(79)	(116)
Deferred income taxes	(77)	1,059
Non-cash restructuring and impairment charges	30	39
Gain on Scott Safety business divestiture	(114)	0
Equity-based compensation	56	81
Other	(24)	1
Changes in assets and liabilities, excluding acquisitions and divestitures:
Accounts receivable	108	(21)
Inventories	(300)	(370)
Other assets	15	(150)
Restructuring reserves	(12)	47
Accounts payable and accrued liabilities	(521)	(599)
Accrued income taxes	254	(1,931)
Cash provided (used) by operating activities	533	(1,519)
Investing Activities
Capital expenditures	(497)	(634)
Sale of property, plant and equipment	10	18
Acquisition of businesses, net of cash acquired	(15)	(6)
Business divestitures	2,114	180
Changes in long-term investments	(14)	(30)
Cash provided (used) by investing activities	1,598	(472)
Financing Activities
Increase (decrease) in short-term debt - net	(100)	55
Increase in long-term debt	886	1,552
Repayment of long-term debt	(2,328)	(831)
Debt financing costs	(4)	(17)
Stock repurchases	(199)	(119)
Payment of cash dividends	(473)	(235)
Proceeds from the exercise of stock options	36	88
Employee equity-based compensation withholding taxes	(37)	(33)
Dividends paid to noncontrolling interests	(46)	(78)
Dividend from Adient spin-off	0	2,050
Cash transferred to Adient related to spin-off	0	(665)
Cash paid related to prior acquistions	0	(37)
Other	11	14
Cash provided (used) by financing activities	(2,254)	1,744
Effect of exchange rate changes on cash and cash equivalents	61	(25)
Change in cash held for sale	9	105
Decrease in cash and cash equivalents	(53)	(167)
Cash and cash equivalents at beginning of period	321	579
Cash and cash equivalents at end of period	$ 268	$ 412