Basis of Presentation (Unaudited) (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 855	$ 797	$ 1,687	$ 1,536
Net earnings	$ 552	$ 517	$ 1,192	$ 1,073
Diluted earnings per share	$ 3.15	$ 2.85	$ 6.78	$ 5.88
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 98	$ 137	$ 213	$ 266
Net earnings	$ 63	$ 89	$ 138	$ 173
Diluted earnings per share	$ 0.36	$ 0.49	$ 0.78	$ 0.95