Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Loss Contingency, Range of Possible Loss, Portion Not Accrued	$ 1,094			$ 1,094		$ 1,077
Letters of Credit Outstanding, Amount	3,640			3,640		3,769
Increase/(Decrease) in (Loss)/earnings from operations due to change in accounting estimate	(38)		$ (23)	(787)	$ 152
737 MAX customer concessions and other considerations liability	6,000			6,000
Base U.S. National Defense Spending	740,500			740,500
Contingent On Customer Negotiations
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	3,400			3,400
Lower Customer Delivery Payments
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	1,600			1,600
Cash Payments To Customers
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	800			800
Customer Concessions
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	200			200
Within Next Two fiscal Years
Commitments And Contingencies [Line Items]
Abnormal Production cost.				5,000
Within Current fiscal Year [Member]
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	200			200
Within Next fiscal Year [Member]
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	400			400
Financing Commitment
Commitments And Contingencies [Line Items]
Other Commitment	12,571			12,571		13,377
Joint venture
Commitments And Contingencies [Line Items]
Other Commitment	243			243
Total Contractual Trade-In Commitment | Commercial Aircraft Commitments
Commitments And Contingencies [Line Items]
Other Commitment	958			958		1,407
Net Amounts Payable to Customers Related to Probable Contractual Trade-In Commitments | Commercial Aircraft Commitments
Commitments And Contingencies [Line Items]
Other Commitment	601			601		711
Fair Value of Trade In Value of Aircraft | Commercial Aircraft Commitments
Commitments And Contingencies [Line Items]
Other Commitment	590			590		678
KC-46A Tanker
Commitments And Contingencies [Line Items]
Contract Value	15,000			15,000
Increase/(Decrease) in (Loss)/earnings from operations due to change in accounting estimate				1,045
KC-46A Tanker | Capitalized Precontract Costs
Commitments And Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	420			420
KC-46A Tanker | Potential Termination Liabilities
Commitments And Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	982			982
KC-46A Tanker Remote Vision System
Commitments And Contingencies [Line Items]
Increase/(Decrease) in (Loss)/earnings from operations due to change in accounting estimate		$ 551
B-737
Commitments And Contingencies [Line Items]
Additional expenses as a result of the 737 MAX grounding				239
Aircraft Program Costs, Increase						6,300
Abnormal Production cost.	590			2,099
737 MAX customer concessions and other considerations liability	$ 5,981			$ 5,981		7,389
B737NG Structure (Picklefork)
Commitments And Contingencies [Line Items]
Cost of Goods and Services Sold		$ 336				$ 135