Basis of Presentation (Unaudited) Contract Estimates (Details 1) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Change in Accounting Estimate [Line Items]
Revenue	$ 124	$ 142	$ 385	$ 462
Operating income	985	951	2,913	2,833
Net earnings	$ 986	$ 933	$ 2,859	$ 2,657
Diluted earnings per share	$ 5.89	$ 5.49	$ 17.05	$ 15.60
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating income	$ 123	$ 125	$ 359	$ 421
Net earnings	$ 97	$ 99	$ 284	$ 333
Diluted earnings per share	$ 0.58	$ 0.58	$ 1.69	$ 1.96