Income Taxes (Unrecognized Tax Benefit Changes) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, Percent	0.20%	45.10%		17.00%	(31.50%)
Effective Income Tax Rate Reconciliation, Change in U.K. Enacted Tax Rate, Amount				$ 73
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount					$ 3,200
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount					228
Effective Income Tax Rate Reconciliation, Deferred Tax Assets, Amount					430
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 9	$ 12		28	$ 33
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	158			158		$ 141
Effective Income Tax Reconciliation, Reorganization, Amount	244			244
Forcepoint
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount				148
Collins Aerospace military Global Positioning System (GPS) and space-based precision optics businesses
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount		$ 206
Minimum [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change	45			45
Minimum [Member] | Forecast [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, Tax Settlement, Amount			$ 20
Maximum [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change	$ 440			$ 440
Maximum [Member] | Forecast [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, Tax Settlement, Amount			$ 100