Quarterly Financial Data (Schedule Of Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 28,341	$ 25,146	$ 24,258	$ 23,382	$ 24,770	$ 24,223	$ 23,051	$ 21,961	$ 101,127	$ 94,005	$ 93,496
Cost of Revenue	22,090	21,040	19,536	18,824	19,881	19,956	18,702	18,073	81,490	76,612	79,026
Earnings from operations	4,175	2,227	2,710	2,875	2,978	2,630	2,530	2,206	11,987	10,344	6,527
Net earnings	$ 3,424	$ 2,363	$ 2,196	$ 2,477	$ 3,320	$ 1,810	$ 1,749	$ 1,579	$ 10,460	$ 8,458	$ 5,034
Income (Loss) from Continuing Operations, Per Basic Share									$ 18.05	$ 14.03	$ 7.92
Basic earnings per share	$ 6.00	$ 4.11	$ 3.77	$ 4.19	$ 5.57	$ 3.03	$ 2.91	$ 2.57	18.05	14.03	7.92
Income (Loss) from Continuing Operations, Per Diluted Share									17.85	13.85	7.83
Diluted earnings per share	$ 5.93	$ 4.07	$ 3.73	$ 4.15	$ 5.49	$ 2.99	$ 2.87	$ 2.54	$ 17.85	$ 13.85	$ 7.83