Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 249	$ 180
Liabilities assumed	(5)	(5)
Contingent/deferred purchase consideration	(44)	(35)
Net cash outflow for current year acquisitions	200	140
Interest paid	199	98
Income taxes paid, net of refunds	$ 136	$ 131