Quarterly Financial Data (Narrative) (Details) - USD ($)	1 Months Ended			3 Months Ended								12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Quarterly Financial Information [Line Items]
Effective Income Tax Rate Reconciliation, Impact of tax reform legislation, Amount				$ 1,051,000,000
Inventory Write-down										$ 1,235,000,000
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.												$ 14,000,000	$ (912,000,000)	$ (224,000,000)
Incremental tax benefit related to tax basis adjustment									$ 440,000,000
Cash dividends declared, per share	$ 1.71	$ 1.42	$ 1.09	$ 3.13		$ 2.84		$ 2.51		$ 2.18		$ 5.97	$ 4.69	$ 3.82
Pension Plans [Member]
Schedule of Quarterly Financial Information [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment												$ (1,000,000)	$ (40,000,000)	$ (290,000,000)
B747 aircraft [Member]
Schedule of Quarterly Financial Information [Line Items]
Reach-forward loss on commercial aircraft										$ (1,188,000,000)	$ (70,000,000)
KC-46A Tanker [Member]
Schedule of Quarterly Financial Information [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.					$ (329,000,000)		$ (142,000,000)	$ (312,000,000)		$ (573,000,000)	$ (243,000,000)	$ (471,000,000)	$ (1,128,000,000)	$ (835,000,000)
Commercial Crew [Member]
Schedule of Quarterly Financial Information [Line Items]
Increase/(Decrease) in Earnings from operations due to change in accounting estimate.									162,000,000
Tax Year 2011-2012 [Member]
Schedule of Quarterly Financial Information [Line Items]
Tax benefit related to settlement of federal tax audit									$ 177,000,000