Basis of Presentation (Unaudited) (Details 1) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Change in Accounting Estimate [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 133	$ 145
Operating Income (Loss)	854	862
Net earnings	$ 739	$ 650
Earnings Per Share, Diluted	$ 4.21	$ 3.69
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 116	$ 141
Net earnings	$ 92	$ 92
Earnings Per Share, Diluted	$ 0.52	$ 0.52