Revenue (Impact of Adjustments in Contract Estimates) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 39,350	$ 36,193	$ 30,973
Operating earnings	$ 4,648	$ 4,457	$ 4,236
Diluted earnings per share	$ 11.98	$ 11.18	$ 9.56
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 342	$ 377	$ 292
Operating earnings	$ 271	$ 345	$ 323
Diluted earnings per share	$ 0.74	$ 0.91	$ 0.69