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, 2020	Jun. 30, 2019
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 752	$ 8,593
Liabilities assumed	(29)	(2,718)
Non-controlling interests assumed	0	(309)
Contingent/deferred purchase consideration	(161)	(66)
Net cash outflow for current year acquisitions	562	5,500
Interest paid	248	141
Income taxes paid, net of refunds	$ 227	$ 327