Employee Benefit Plans (Schedule of Pension Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss arising during the period	$ 202	$ 543	$ 1,819
Amortization of actuarial gain	373	170	344
Current year prior service cost (credit)	(2,095)	6	22
Amortization of prior service cost	(373)	(228)	$ (344)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss arising during the period	155	553
Amortization of actuarial gain	(337)	(265)
Current year prior service cost (credit)	(2,088)	6
Amortization of prior service cost	(51)	(17)
Net settlement and curtailment	(34)	57
Separation of Carrier and Otis	(763)	0
Other	81	34
Total recognized in other comprehensive (income) loss	(3,037)	368
Net recognized in net periodic benefit (income) cost and other comprehensive loss	$ (3,466)	(135)
Pension Plan [Member] | Continuing operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss arising during the period		434
Amortization of actuarial gain		(245)
Current year prior service cost (credit)		0
Amortization of prior service cost		(16)
Net settlement and curtailment		62
Separation of Carrier and Otis		0
Other		36
Total recognized in other comprehensive (income) loss		271
Net recognized in net periodic benefit (income) cost and other comprehensive loss		(232)
Pension Plan [Member] | Discontinued Operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss arising during the period		119
Amortization of actuarial gain		(20)
Current year prior service cost (credit)		6
Amortization of prior service cost		(1)
Net settlement and curtailment		(5)
Separation of Carrier and Otis		0
Other		(2)
Total recognized in other comprehensive (income) loss		97
Net recognized in net periodic benefit (income) cost and other comprehensive loss		$ 97