Basis of Presentation (Unaudited) (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 739	$ 780
Net earnings	$ 556	$ 484
Diluted earnings per share	$ 3.03	$ 2.41
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 129	$ 187
Net earnings	$ 84	$ 122
Diluted earnings per share	$ 0.46	$ 0.61