CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended				6 Months Ended		9 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019
Operating Activities
Net income	$ 269	$ 102	$ 794	$ 403	$ 371	$ 1,197
Adjustments to reconcile net income from operations to net cash flows provided by operating activities, net of acquisitions and dispositions
Depreciation and amortization					159	167
Deferred income tax provision					135	(57)
Stock compensation costs					35	22
Equity method investment net earnings	(57)		(80)		(86)	(120)
Distributions from equity method investments					49	46
Impairment charge on minority-owned joint venture investments					72		$ 0
Changes in operating assets and liabilities
Accounts receivable, net					27	(206)
Contract assets, current					(140)	(43)
Inventories, net					(325)	(340)
Other assets, current					32	16
Accounts payable and accrued liabilities					152	(173)
Contract liabilities, current					37	(16)
Pension contributions					(27)	(27)
Other operating activities, net					65	(95)
Net cash flows provided by operating activities					556	371
Investing Activities
Capital expenditures					(94)	(89)
(Payment) receipt from settlement of derivative contracts					(23)	1
Other investing activities, net					14	8
Net cash flows used in investing activities					(103)	(80)
Financing Activities
(Decrease) increase in short-term borrowings, net					(17)	45
Issuance of long-term debt					11,734	77
Repayment of long-term debt					(36)	(37)
Dividends paid to non-controlling interest					(8)	(3)
Net transfers to UTC					(10,359)	(548)
Other financing activities, net					1	(26)
Net cash flows provided by (used in) financing activities					1,315	(492)
Effect of Exchange Rate on Cash and Cash Equivalents [Abstract]
Effect of foreign exchange rate changes on cash and cash equivalents					(17)	7
Net increase (decrease) in cash and cash equivalents and restricted cash					1,751	(194)
Cash, cash equivalents and restricted cash, beginning of period		$ 957		$ 1,134	957	1,134	$ 1,134
Cash, cash equivalents and restricted cash, end of period	2,708		940		2,708	940
Less: restricted cash	4		4		4	4
Cash and cash equivalents, end of period	$ 2,704		$ 936		$ 2,704	$ 936