Liabilities, Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Liabilities Commitments And Contingencies [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.						$ (942.0)	$ (111.0)	$ (190.0)
Amount by which estimated range of reasonably possible remediation costs exceeded recorded liabilities	$ 1,095.0				$ 1,077.0	1,095.0	1,077.0
Contingent liabilities on outstanding letters of credit agreements and surety bonds	4,238.0				3,769.0	4,238.0	3,769.0
Cash surrender value of life insurance policies	395.0				448.0	395.0	448.0
Total value of loans against underlying life insurance policies	382.0				431.0	382.0	431.0
Abnormal Production Costs			$ 133.0	$ 137.0
737 MAX Customer Concessions & Other Considerations Liability	5,537.0				7,389.0	5,537.0	7,389.0
Deferred Prosecution Agreement Liability	744.0					744.0
Deferred Prosecution Agreement Liability - Total Obligation	2,510.0					2,510.0
Contingent On Customer Negotiations [Member]
Liabilities Commitments And Contingencies [Line Items]
737 MAX Customer Concessions & Other Considerations Liability	2,500.0					2,500.0
Lower Customer Delivery Payments [Member]
Liabilities Commitments And Contingencies [Line Items]
737 MAX Customer Concessions & Other Considerations Liability	2,300.0					2,300.0
Cash Payments to Customers [Member]
Liabilities Commitments And Contingencies [Line Items]
737 MAX Customer Concessions & Other Considerations Liability	600.0					600.0
Customer Concessions [Member]
Liabilities Commitments And Contingencies [Line Items]
737 MAX Customer Concessions & Other Considerations Liability	100.0					100.0
Criminal Monetary Penalty [Member]
Liabilities Commitments And Contingencies [Line Items]
Deferred Prosecution Agreement Liability	243.6					243.6
Beneficiary Compensation [Member]
Liabilities Commitments And Contingencies [Line Items]
Deferred Prosecution Agreement Liability	500.0					500.0
Total Criminal Monetary Penalty and Beneficiary Compensation [Member]
Liabilities Commitments And Contingencies [Line Items]
Deferred Prosecution Agreement Liability	743.6					743.6
737 MAX Customer Concessions & Other Considerations Liability [Member]
Liabilities Commitments And Contingencies [Line Items]
Deferred Prosecution Agreement Liability	1,770.0					1,770.0
Within Current fiscal Year [Member]
Liabilities Commitments And Contingencies [Line Items]
737 MAX Customer Concessions & Other Considerations Liability	300.0					300.0
Within Next fiscal Year [Member]
Liabilities Commitments And Contingencies [Line Items]
Abnormal Production Costs						5,000.0
737 MAX Customer Concessions & Other Considerations Liability	300.0					300.0
B737NG Structure Picklefork [Member]
Liabilities Commitments And Contingencies [Line Items]
Cost of Goods and Services Sold				336.0			135.0
737 MAX Storage, Pilot Training and Software Updates [Member]
Liabilities Commitments And Contingencies [Line Items]
Additional expenses as a result of the 737 MAX grounding						416.0	328.0
B-737 Aircraft [Member]
Liabilities Commitments And Contingencies [Line Items]
Abnormal Production Costs						2,567.0
737 MAX Customer Concessions & Other Considerations Liability	5,537.0				7,389.0	5,537.0	7,389.0		$ 6,110.0
Concessions & Other In-Kind Considerations to Customers						(162.0)	(133.0)
Accrual for 737 MAX Customer Concessions and Other Considerations Liability						498.0	2,649.0
Commercial Aircraft Commitments [Member] | Total Contractual Trade In Value Maximum [Member]
Liabilities Commitments And Contingencies [Line Items]
Other Commitment	950.0				1,407.0	950.0	1,407.0
Commercial Aircraft Commitments [Member] | Probable Contractual Trade In Value [Member]
Liabilities Commitments And Contingencies [Line Items]
Other Commitment	580.0				678.0	580.0	678.0
Commercial Aircraft Commitments [Member] | Net amounts payable to customers related to probable contractual trade-in commitments [Member]
Liabilities Commitments And Contingencies [Line Items]
Other Commitment	599.0				711.0	599.0	711.0
Financing Commitment [Member]
Liabilities Commitments And Contingencies [Line Items]
Other Commitment	11,512.0				13,377.0	11,512.0	13,377.0
Financing Commitment [Member] | External Credit Rating, Non Investment Grade [Member]
Liabilities Commitments And Contingencies [Line Items]
Other Commitment	11,512.0					11,512.0
Joint Venture [Member]
Liabilities Commitments And Contingencies [Line Items]
Other Commitment	243.0					243.0
KC-46A Tanker [Member]
Liabilities Commitments And Contingencies [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.	275.0	$ 67.0	$ 151.0	827.0	$ 108.0	1,320.0	$ (148.0)	$ (736.0)
Contract Value	15,000.0					15,000.0
KC-46A Tanker [Member] | Capitalized Precontract Costs [Member]
Liabilities Commitments And Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	463.0					463.0
KC-46A Tanker [Member] | Potential Termination Liabilities [Member]
Liabilities Commitments And Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 1,281.0					$ 1,281.0
KC-46A Tanker Remote Vision System [Member]
Liabilities Commitments And Contingencies [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.				$ 551.0