Basis of Presentation (Unaudited) (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 813	$ 820	$ 1,593	$ 1,665
Net earnings	$ 531	$ 511	$ 1,015	$ 1,090
Diluted earnings per share	$ 2.74	$ 2.37	$ 5.15	$ 5.01
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 162	$ 165	$ 349	$ 362
Net earnings	$ 105	$ 107	$ 227	$ 235
Diluted earnings per share	$ 0.54	$ 0.50	$ 1.15	$ 1.08