Income Taxes (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended	12 Months Ended
	Apr. 30, 2020	Dec. 31, 2020	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Undistributed Earnings of Foreign Subsidiaries		$ 12,000			$ 12,000
Income tax expense					575	$ 421	$ 1,098
Income from continuing operations before income taxes					2,353	(4,152)	(2,504)
Goodwill impairment			$ 3,200		3,183	0	0
Net deferred tax charges resulting from the Separation Transactions and Raytheon Merger					367
Disposals of businesses					177	0	0
Tax expense related to revaluation of tax benefit for certain international tax incentives					49
Foreign Derived Intangible Income (FDII)					83	138	102
Tax audit settlements		(25)			0	290	0
U.S. research and development credit					142	101	73
Effective Income Tax Rate Reconciliation, Deduction, Amount							744
Unrecognized Tax Benefits		1,225			1,225	1,347	1,619	$ 1,189
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		1,216			1,216
Separation of Carrier and Otis	$ 439				(439)
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	165	141			141	249	255
Tax Settlement Gain (Loss) Noncash						307
IRS audit of 2014, 2015 and 2016 tax years | Interest Income [Member]
Income Tax Contingency [Line Items]
Tax Settlement Gain (Loss) Noncash						56
IRS audit of 2014, Rockwell Collins subsidiary
Income Tax Contingency [Line Items]
Tax Settlement Gain (Loss) Noncash						40
Reversal of indemnity asset
Income Tax Contingency [Line Items]
Tax Settlement Gain (Loss) Noncash						(23)
Various federal, state and non-US statute of limitations expirations and settlements [Member]
Income Tax Contingency [Line Items]
Tax Settlement Gain (Loss) Noncash						18
Various federal, state and non-US statute of limitations expirations and settlements [Member] | Interest Income [Member]
Income Tax Contingency [Line Items]
Tax Settlement Gain (Loss) Noncash						5
Minimum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible		165			165
Maximum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible		$ 475			$ 475
Forecast [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Tax audit settlements				$ (50)
Forecast [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Tax audit settlements				$ (100)
Raytheon Company [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	15
Unrecognized Tax Benefits, Increase Resulting from Acquisition	$ 273
Discontinued Operations [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits						437	551
Unrecognized Tax Benefits, Interest on Income Taxes Accrued						$ 155	$ 155