Basis of Presentation (Unaudited) (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 832	$ 739
Net earnings	$ 640	$ 556
Diluted earnings per share	$ 3.63	$ 3.03
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 115	$ 129
Net earnings	$ 75	$ 84
Diluted earnings per share	$ 0.43	$ 0.46