Inventories (Narrative) (Details) $ in Millions	Mar. 31, 2018 USD ($) aircraft	Dec. 31, 2017 USD ($)
Inventory [Line Items]
Long-term contracts in progress	$ 1,926	$ 1,854
Other Inventory, Gross	6,369	6,673
Airplane Program 787 [Member]
Inventory [Line Items]
Inventory, Work in Process, Gross	30,049	30,695
Amount of Deferred Costs Related to Long-term Contracts	24,690	25,358
Advances on Inventory Purchases	2,839	3,189
Unamortized Tooling	3,042	3,173
Recovered Production Costs Excess Recoverable Under Existing Firm Orders	22,034
Unrecovered Production Costs, Excess Unrecoverable under Existing Firm Orders	5,698
Airplane Program 747 [Member]
Inventory [Line Items]
Unamortized Tooling	138	151
Recovered Production Costs Excess Recoverable Under Existing Firm Orders	$ 133
Unsold Aircraft | aircraft	1
Ula [Member]
Inventory [Line Items]
Inventory Amount, Unpriced Change Orders for Long-term Contracts or Programs	$ 120
Long-term contracts in progress	267	284
Capitalized Precontract Costs [Member]
Inventory [Line Items]
Inventory Amount, Unpriced Change Orders for Long-term Contracts or Programs	691	933
Early Issue Sales Consideration [Member]
Inventory [Line Items]
Inventory Amount, Unpriced Change Orders for Long-term Contracts or Programs	$ 2,958	$ 2,976