Inventories (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventories [Line Items]
Long-term contracts in progress	$ 823	$ 1,187
Commercial spare parts, used aircraft, general stock materials and other	10,739	9,419
777X reach-forward loss	942	111	$ 190
Airplane Program 787 [Member]
Inventories [Line Items]
Deferred production costs	14,976	18,716
Supplier advances	1,865	2,202
Unamortized tooling and other non-recurring costs	1,863	2,092
Deferred production, unamortized tooling and other nonrecurring costs to be recovered from firm orders at the balance sheet date	12,165
Deferred production, unamortized tooling and other nonrecurring costs to be recovered from future orders	4,674
Airplane Program 737 [Member]
Inventories [Line Items]
Deferred production costs	2,159	1,313
Unamortized tooling and other non-recurring costs	480	521
Deferred production, unamortized tooling and other nonrecurring costs to be recovered from firm orders at the balance sheet date	2,560
Deferred production, unamortized tooling and other nonrecurring costs to be recovered from future orders	79
Airplane Program 777x [Member]
Inventories [Line Items]
Unamortized tooling and other non-recurring costs	3,295	2,914
777X reach-forward loss	6,493
ULA [Member]
Inventories [Line Items]
Long-term contracts in progress	17	176
Capitalized Precontract Costs [Member]
Inventories [Line Items]
Inventory subject to uncertainty	733	711
Early Issue Sales Consideration [Member]
Inventories [Line Items]
Inventory subject to uncertainty	$ 2,992	$ 2,863