Income Taxes (Schedule of Earnings Before Income Taxes and Provision For Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Earnings before income taxes	$ 10,589	$ 9,924	$ 9,615
United States federal and state:
Current	1,662	(39)	(56)
Deferred	(384)	293	117
Total United States	1,278	254	61
Outside United States:
Current	3,146	2,625	2,762
Deferred	(117)	(111)	(135)
Total outside United States	3,029	2,514	2,627
Total provision for income taxes	$ 4,307	$ 2,768	$ 2,688