Acquisitions and Dispositions (Allocation Of Acquisition Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Cash	$ 888	$ 694
Estimated fair value of deferred/contingent consideration	153	183	$ 66
Fair value of previously-held equity method investment	390	0	0
Total consideration	1,400	877
Allocation of purchase price:
Goodwill	16,317	$ 15,517	$ 14,671
Current Fiscal Period Acquisitions
Business Acquisition [Line Items]
Cash	888
Estimated fair value of deferred/contingent consideration	153
Fair value of previously-held equity method investment	390
Total consideration	1,431
Allocation of purchase price:
Cash and cash equivalents	11
Cash and cash equivalents held in a fiduciary capacity	18
Net receivables	77
Other current assets	20
Goodwill	1,045
Other intangible assets	508
Fixed assets, net	5
Right of use assets	36
Other assets	6
Total assets acquired	1,726
Current liabilities	72
Fiduciary liabilities	18
Long-term lease liabilities	36
Other liabilities	105
Total liabilities assumed	231
Non-controlling interests	64
Net assets acquired	$ 1,431