Acquisitions and Dispositions (Allocation Of Acquisition Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Cash	$ 24
Estimated fair value of deferred/contingent consideration	4	$ 0
Total consideration	28
Allocation of purchase price:
Goodwill	16,254	$ 15,458	$ 16,317	$ 15,517
Current Fiscal Period Acquisitions
Business Acquisition [Line Items]
Cash	24
Estimated fair value of deferred/contingent consideration	4
Total consideration	28
Allocation of purchase price:
Net receivables	1
Other current assets	2
Goodwill	17
Other intangible assets	10
Total assets acquired	30
Current liabilities	1
Other liabilities	1
Total liabilities assumed	2
Net assets acquired	$ 28