Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 795	$ 8,619
Liabilities assumed	(73)	(2,758)
Non-controlling interests assumed	0	(295)
Contingent/deferred purchase consideration	(163)	(66)
Net cash outflow for current year acquisitions	559	5,500
Interest paid	437	387
Income taxes paid, net of refunds	$ 414	$ 442