Investments (Schedule Of Ownership Percentages And Balances Of Equity Method Investments) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Equity method investments	[1]	$ 936	$ 1,031
Defense, Space & Security | United Launch Alliance [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%	50.00%
Equity method investments		$ 735	$ 771
Commercial Airplanes, Defense, Space & Security, and Global Services [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 201	$ 260

[1] Dividends received were $149 and $164 during 2020 and 2019. Retained earnings at December 31, 2020 include undistributed earnings from our equity method investments of $148.