Acquisitions and Dispositions (Allocation Of Acquisition Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Cash	$ 11	$ 24
Estimated fair value of deferred/contingent consideration	4	4
Total consideration	15	28
Allocation of purchase price:
Goodwill	16,300	$ 16,254	$ 16,251	$ 16,317
Current Fiscal Period Acquisitions
Business Acquisition [Line Items]
Cash	11
Estimated fair value of deferred/contingent consideration	4
Total consideration	15
Allocation of purchase price:
Net receivables	2
Goodwill	11
Other intangible assets	4
Total assets acquired	17
Current liabilities	2
Total liabilities assumed	2
Net assets acquired	$ 15