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, 2021	Jun. 30, 2020
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 561	$ 752
Liabilities assumed	(60)	(29)
Contingent/deferred purchase consideration	(138)	(161)
Net cash outflow for current year acquisitions	363	562
Interest paid	234	248
Income taxes paid, net of refunds	$ 403	$ 227