Goodwill and Other Intangible Assets - Schedule of Changes in the Net Carrying Amount of Goodwill (Details) $ in Millions	6 Months Ended
	Jun. 30, 2025 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 15,234
Goodwill related to current year acquisitions	362
Measurement period adjustments related to prior year acquisitions	(28)
Foreign currency translation and other	456
Ending balance	16,024
Risk Capital
Goodwill [Roll Forward]
Beginning balance	8,785
Goodwill related to current year acquisitions	346
Measurement period adjustments related to prior year acquisitions	(11)
Foreign currency translation and other	301
Ending balance	9,421
Human Capital
Goodwill [Roll Forward]
Beginning balance	6,449
Goodwill related to current year acquisitions	16
Measurement period adjustments related to prior year acquisitions	(17)
Foreign currency translation and other	155
Ending balance	$ 6,603