Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term borrowings	$ (538)	$ (34)
Reimbursement of tax payments | UTC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accounts payable, related parties	239
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term receivables	61	62
Customer financing notes receivable	99	62
Short-term borrowings	(538)	(34)
Long-term debt (excluding finance leases)	(5,550)	0
Long-term liabilities	(275)	(4)
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term receivables	62	62
Customer financing notes receivable	99	62
Short-term borrowings	(538)	(34)
Long-term debt (excluding finance leases)	(5,760)	0
Long-term liabilities	(263)	(4)
Fair Value Level 1 | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term receivables	0	0
Customer financing notes receivable	0	0
Short-term borrowings	0	0
Long-term debt (excluding finance leases)	0
Long-term liabilities	0	0
Fair Value Level 2 | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term receivables	62	62
Customer financing notes receivable	99	62
Short-term borrowings	(538)	(34)
Long-term debt (excluding finance leases)	(5,760)
Long-term liabilities	(263)	(4)
Fair Value Level 3 | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term receivables	0	0
Customer financing notes receivable	0	0
Short-term borrowings	0	0
Long-term debt (excluding finance leases)
Long-term liabilities	0	0
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	51	3
Derivative Assets	51	9
Derivative liabilities	(33)	(5)
Fair Value, Recurring | Fair Value Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	51	3
Derivative Assets	0	0
Derivative liabilities	0	0
Fair Value, Recurring | Fair Value Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Derivative Assets	51	9
Derivative liabilities	(33)	(5)
Fair Value, Recurring | Fair Value Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Derivative Assets	0	0
Derivative liabilities	$ 0	$ 0