INCOME TAXES - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019	Jun. 30, 2020 USD ($)	Jun. 30, 2019	Apr. 03, 2020 USD ($) installment	Apr. 02, 2020 USD ($)
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Effective income tax rate reconciliation, percent	28.20%	7.60%	44.60%	14.60%
Effective income tax rate reconciliation, tax settlement, amount	$ 149
Effective income tax rate reconciliation, change in deferred tax assets valuation allowance			$ 51
Effective income tax rate reconciliation, repatriation of foreign earnings, amount			46
Effective income tax rate reconciliation, nondeductible expense, impairment losses			71
Increase (decrease) in unrecognized tax benefits	37
Deferred tax assets, unrealized currency losses	27		27
United Technologies Corp
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Tax cuts and jobs act, transition tax for accumulated foreign earnings, liability, noncurrent					$ 701
Unrecognized tax benefits, number of annual installments | installment					6
Accrued Liabilities | United Technologies Corp
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Tax cuts and jobs act, transition tax for accumulated foreign earnings, liability, current						$ 68
Accrued income taxes, current					$ 6
Other Noncurrent Liabilities | United Technologies Corp
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Accrued income taxes, noncurrent					$ 453
Maximum
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Decrease in unrecognized tax benefits is reasonably possible	$ 15		$ 15