Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 8,593	$ 204
Liabilities assumed	(2,718)	(28)
Non-controlling interests assumed	(309)	0
Contingent/deferred purchase consideration	(66)	(32)
Net cash outflow for current year acquisitions	5,500	144
Interest paid	141	107
Income taxes paid, net of refunds	$ 327	$ 349