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, 2023	Sep. 30, 2022
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity	$ 760	$ 236
Acquisition-related deposit	0	24
Fiduciary liabilities assumed	(14)	(2)
Liabilities assumed	(98)	(28)
Contingent/deferred purchase consideration	(29)	(17)
Net cash outflow for acquisitions	619	213
Interest paid	427	388
Income taxes paid, net of refunds	$ 699	$ 697