Income Taxes (Significant Components Of Deferred Tax Assets Net Of Deferred Tax Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Valuation Allowance [Line Items]
Inventory and long-term contract methods of income recognition		$ (4,313)	$ (6,048)
Pension benefits		3,029	3,495
Fixed assets, intangibles and goodwill		(1,645)	(1,544)
737 MAX customer concessions and other considerations		1,253	1,626
Net operating loss, credit and capital loss carryovers(1)	[1]	1,182	696
Other postretirement benefit obligations		1,023	1,120
Other employee benefits		957	849
Accrued expenses and reserves		808	628
Customer and commercial financing		(180)	(268)
Other		56	166
Gross deferred tax assets/(liabilities) before valuation allowance		2,170	388
Valuation allowance		3,094	118
Net deferred tax (liabilities)/assets		924	270
Deferred tax asset for net operating loss and credit carryovers each year through December 31, 2035		793
Deferred tax asset for net operating loss and credit carryovers indefinitely		389
Deferred tax assets		11,600	10,722
Deferred Tax Liabilities, Gross		9,430	$ 10,334
Continuing Operations [Member]
Valuation Allowance [Line Items]
Valuation allowance		2,513
Other Comprehensive Income (Loss) [Member]
Valuation Allowance [Line Items]
Valuation allowance		$ 196

[1] Of the deferred tax asset for net operating loss and credit carryovers, $793 expires on or before December 31, 2040 and $389 may be carried over indefinitely.