Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Interest capitalized	$ 81	$ 110	$ 170
Rental expense for leased properties	307	283	287
Minimum rental payments under capital leases, total	164
Minimum rental payments under operating leases with initial or remaining terms of one year or more, total	1,838
Sublease payments under operating lease	12
Property, plant and equipment included in accounts payable	338	196
Property, Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation	$ 1,556	$ 1,548	$ 1,418