Borrowings and Lines of Credit (Schedule of Issuances of Long-term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018
Debt Instrument [Line Items]
Proceeds from Issuance of Debt		$ 11,000
Notes 2.250% Due 2030 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,000
Debt Instrument, Maturity Year Date	2030
Debt Instrument, Interest Rate, Stated Percentage	2.25%
Notes 3.125% Due 2050 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,000
Debt Instrument, Maturity Year Date	2050
Debt Instrument, Interest Rate, Stated Percentage	3.125%
Otis 3-Year Term Loan due 2023 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,000
Debt Instrument, Maturity Year Date	2023
Carrier 3-Year Term Loan due 2023 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,750
Debt Instrument, Maturity Year Date	2023
Notes 1.923% Due 2023 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 500
Debt Instrument, Maturity Year Date	2023
Debt Instrument, Interest Rate, Stated Percentage	1.923%
Libor plus 0.45% floating rates due 2023 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 500
Debt Instrument, Maturity Year Date	2023
Debt Instrument, Interest Rate, Stated Percentage	0.45%
Notes 2.056% Due 2025 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,300
Debt Instrument, Maturity Year Date	2025
Debt Instrument, Interest Rate, Stated Percentage	2.056%
Notes 2.242% Due 2025 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 2,000
Debt Instrument, Maturity Year Date	2025
Debt Instrument, Interest Rate, Stated Percentage	2.242%
Notes 2.293% Due 2027 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 500
Debt Instrument, Maturity Year Date	2027
Debt Instrument, Interest Rate, Stated Percentage	2.293%
Notes 2.493% Due 2027 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,250
Debt Instrument, Maturity Year Date	2027
Debt Instrument, Interest Rate, Stated Percentage	2.493%
Notes 2.565% Due 2030 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,500
Debt Instrument, Maturity Year Date	2030
Debt Instrument, Interest Rate, Stated Percentage	2.565%
Notes 2.722% Due 2030 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 2,000
Debt Instrument, Maturity Year Date	2030
Debt Instrument, Interest Rate, Stated Percentage	2.722%
Notes 3.112% Due 2040 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 750
Debt Instrument, Maturity Year Date	2040
Debt Instrument, Interest Rate, Stated Percentage	3.112%
Notes 3.377% Due 2040 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 1,500
Debt Instrument, Maturity Year Date	2040
Debt Instrument, Interest Rate, Stated Percentage	3.377%
Notes 3.362% Due 2050 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 750
Debt Instrument, Maturity Year Date	2050
Debt Instrument, Interest Rate, Stated Percentage	3.362%
Notes 3.577% Due 2050 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 2,000
Debt Instrument, Maturity Year Date	2050
Debt Instrument, Interest Rate, Stated Percentage	3.577%