Summary Of Significant Accounting Policies (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) segments $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($) $ / shares	Jan. 01, 2020 USD ($)	Dec. 31, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of Reportable Segments | segments						4
Net cash (used)/provided by operating activities						$ (18,410)	$ (2,446)	$ 15,322
Debt Instrument, Face Amount	$ 4,900		$ 25,000			4,900
Cash, Cash Equivalents, and Short-term Investments	25,600					25,600
Debt and Lease Obligation	63,583				$ 27,302	63,583	27,302
Commercial paper					6,109		6,109
Line of Credit Facility, Maximum Borrowing Capacity				$ 13,825
Increase/(Decrease) in Revenue due to change in accounting estimate						(359)	54	137
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.						$ (942)	$ (111)	$ (190)
Earnings Per Share impact, change in accounting estimate | $ / shares						$ (1.37)	$ (0.06)	$ (0.29)
Reinsurance revenues						$ 129	$ 151	$ 145
Reinsurance costs						136	150	136
Research and development expense, net						2,476	3,219	3,269
Accounts payable	12,928				15,553	12,928	15,553
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 18,075				8,300	$ 18,075	8,300	(410)		$ (1,713)
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Equity Method Investment, Ownership Percentage	20.00%					20.00%
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Equity Method Investment, Ownership Percentage	50.00%					50.00%
Commercial Airplanes | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Standard warranty term						3 years
Commercial Airplanes | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Standard warranty term						4 years
Developed Technology [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						4 years
Developed Technology [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						14 years
Product Know-How [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						6 years
Product Know-How [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						30 years
Customer Base [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						3 years
Customer Base [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						17 years
Distribution Rights [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						3 years
Distribution Rights [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						27 years
Other Intangible Assets [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						1 year
Other Intangible Assets [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-lived acquired intangible assets, useful lives (in years)						32 years
Buildings And Land Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives (in years)						10 years
Buildings And Land Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives (in years)						40 years
Machinery And Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives (in years)						4 years
Machinery And Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives (in years)						20 years
Capitalized Internal Use Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives (in years)						5 years
7372 Services, Prepackaged Software [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives (in years)						10 years
Bank Overdrafts [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts payable	$ 74				101	$ 74	101
Bid And Proposal Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Research and development expense, net						224	214	234
KC-46A Tanker [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.	275	$ 67	$ 151	827	108	1,320	(148)	(736)
Commercial Crew [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.					410		(489)
2020 [Member] | KC-46A Tanker [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.						(953)
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(38,610)				$ (50,644)	(38,610)	$ (50,644)	$ (55,941)		$ (49,618)
Delayed Draw Term Loan Facility [Member]
Summary Of Significant Accounting Policies [Line Items]
Proceeds from Long-term Lines of Credit				$ 13,825
Revolving Credit Facility [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt Instrument, Unused Borrowing Capacity, Amount	9,500					9,500
Line of Credit Facility, Maximum Borrowing Capacity	9,473					9,473
364-day Revolving Credit Facility [Member]
Summary Of Significant Accounting Policies [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	3,100					3,100
Supply Chain Financing [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts Payable, Trade	3,800					3,800
Senior Notes [Member] | 2021 [Member]
Summary Of Significant Accounting Policies [Line Items]
Long-term Debt, Current Maturities	$ 1,500					$ 1,500
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest									$ 162
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest									$ 162