Basis of Presentation (Unaudited) (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 826	$ 794	$ 2,362	$ 2,387
Net earnings	$ 602	$ 516	$ 1,675	$ 1,531
Diluted earnings per share	$ 3.35	$ 2.75	$ 9.23	$ 7.89
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 121	$ 112	$ 387	$ 461
Net earnings	$ 79	$ 73	$ 252	$ 300
Diluted earnings per share	$ 0.44	$ 0.39	$ 1.39	$ 1.55