Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2024

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes in the Net Carrying Amount of Goodwill by Operating Segment

The changes in the net carrying amount of goodwill for the years ended December 31, 2024 and 2023, respectively, are as follows (in millions):

	Risk Capital		Human Capital		Total
Balance as of January 1, 2023	$	6,127	$	2,165	$	8,292
Goodwill related to current year acquisitions	20		3		23
Goodwill related to current year disposals	(1)		—		(1)
Foreign currency translation and other	81		19		100
Balance as of December 31, 2023	$	6,227	$	2,187	$	8,414
Goodwill related to current year acquisitions	2,768		4,357		7,125
Goodwill related to current year disposals	(50)		(32)		(82)
Foreign currency translation and other	(160)		(63)		(223)
Balance as of December 31, 2024	$	8,785	$	6,449	$	15,234

Schedule of Other Intangible Assets by Asset Class

Amortization basis and estimated useful lives by intangible asset type are generally as follows:

Intangible Asset Description	Amortization Basis	Estimated Useful Life
Customer-related and contract-based	In line with underlying cash flows	7 to 23 years
Tradenames	Straight-line	1 to 10.5 years
Technology and other intangibles	Straight-line	5 to 7 years

Other intangible assets by asset class are as follows (in millions):

	2024						2023
As of December 31	Gross Carrying Amount		Accumulated Amortization and Impairment		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization and Impairment		Net Carrying Amount
Customer-related and contract-based	$	7,994	$	2,050	$	5,944	$	1,873	$	1,686	$	187
Tradenames	812		66		746		12		12		—
Technology and other	366		313		53		359		312		47
Total	$	9,172	$	2,429	$	6,743	$	2,244	$	2,010	$	234

Schedule of Estimated Future Amortization Expense on Intangible Assets

The estimated future amortization for finite-lived intangible assets as of December 31, 2024 is as follows (in millions):

	Estimated Future Amortization
For the years ended
2025	$	760
2026	691
2027	633
2028	582
2029	538
Thereafter	3,539
Total	$	6,743