Supplemental Disclosures to the Consolidated Statements of Cash Flows (Supplemental Cash Flow Disclosures) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity	$ 367	$ 1,310
Fiduciary liabilities assumed	(17)	(8)
Liabilities assumed	(43)	(84)
Fair value of previously-held equity investment	(15)	0
Contingent/deferred purchase consideration	(68)	(176)
Net cash outflow for acquisitions	224	1,042
Interest paid	775	538
Income taxes paid, net of refunds	$ 886	$ 922