Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash, and cash and cash equivalents held in a fiduciary capacity	$ 236	$ 601
Acquisition-related deposit	24	0
Fiduciary liabilities assumed	(2)	(17)
Liabilities assumed	(28)	(59)
Contingent/deferred purchase consideration	(17)	(141)
Net cash outflow for acquisitions	213	384
Interest paid	388	407
Income taxes paid, net of refunds	$ 697	$ 686