Contract Asset and Liability (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue from contract with customer [Line Items]
Contract assets	$ 10,238		$ 9,931
Contract liabilities	(12,879)		(12,889)
Net contract liabilities	(2,641)		(2,958)
Contract with Customer, Asset, Change	307
Contract with Customer, Liability, Revenue Recognized	1,705	$ 1,183
Advances received to date on contracts related to precision guided munitions to certain Middle Eastern customers pending U.S. government approval	440
Contract with Customer, Asset, Allowance for Credit Loss	$ 222		$ 177