Other Assets and Other Liabilities (Other Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Other Assets and Other Liabilities [Abstract]
Contingent consideration asset		$ 300
Derivative instruments	$ 103	197
Other current assets	599	494
Other current assets	702	991
Derivative instruments	45	68
South Korean tax deposits	425	319
Other non-current assets	551	547
Other assets	$ 1,021	$ 934