Goodwill and Other Intangible Assets - Schedule of Changes in the Net Carrying Amount of Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2026 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 15,797
Goodwill related to current year acquisitions	190
Foreign currency translation and other	(62)
Ending balance	15,925
Risk Capital
Goodwill [Roll Forward]
Beginning balance	9,551
Goodwill related to current year acquisitions	190
Foreign currency translation and other	(38)
Ending balance	9,703
Human Capital
Goodwill [Roll Forward]
Beginning balance	6,246
Goodwill related to current year acquisitions	0
Foreign currency translation and other	(24)
Ending balance	$ 6,222