Revenue from Contracts with Customers (Tables)

6 Months Ended

Jun. 30, 2025

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregation of Revenue

The following table summarizes revenue from contracts with customers by principal service line (in millions):

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
Commercial Risk Solutions	$	2,178	$	2,015	$	4,180	$	3,823
Reinsurance Solutions	688		635		1,877		1,802
Total Risk Capital (1)	2,866		2,650		6,057		5,625
Health Solutions	772		662		1,798		1,395
Wealth Solutions	519		463		1,038		833
Total Human Capital (1)	1,291		1,125		2,836		2,228
Eliminations	(2)		(15)		(9)		(23)
Total revenue	$	4,155	$	3,760	$	8,884	$	7,830

(1)Includes inter-segment revenue. Refer to Note 16 “Segment Information” for further information.

Consolidated revenue from contracts with customers by geographic area, which is attributed on the basis of where the services are performed, is as follows (in millions):

	Three Months Ended June 30, 2025
	Risk Capital		Human Capital		Corporate/Eliminations		Total
U.S.	$	1,324	$	718	$	(2)	$	2,040
Americas other than U.S.	285		110		—		395
U.K.	411		199		—		610
Ireland	24		22		—		46
Europe, Middle East, & Africa other than U.K. and Ireland	469		165		—		634
Asia Pacific	353		77		—		430
Total revenue	$	2,866	$	1,291	$	(2)	$	4,155

	Three Months Ended June 30, 2024
	Risk Capital		Human Capital		Corporate/Eliminations		Total
U.S.	$	1,217	$	635	$	(15)	$	1,837
Americas other than U.S.	260		102		—		362
U.K.	379		169		—		548
Ireland	20		15		—		35
Europe, Middle East, & Africa other than U.K. and Ireland	428		138		—		566
Asia Pacific	346		66		—		412
Total revenue	$	2,650	$	1,125	$	(15)	$	3,760

	Six Months Ended June 30, 2025
	Risk Capital		Human Capital		Corporate/Eliminations		Total
U.S.	$	2,545	$	1,506	$	(9)	$	4,042
Americas other than U.S.	539		230		—		769
U.K.	841		390		—		1,231
Ireland	46		45		—		91
Europe, Middle East, & Africa other than U.K. and Ireland	1,415		481		—		1,896
Asia Pacific	671		184		—		855
Total revenue	$	6,057	$	2,836	$	(9)	$	8,884

	Six Months Ended June 30, 2024
	Risk Capital		Human Capital		Corporate/Eliminations		Total
U.S.	$	2,295	$	1,077	$	(23)	$	3,349
Americas other than U.S.	487		198		—		685
U.K.	790		341		—		1,131
Ireland	36		32		—		68
Europe, Middle East, & Africa other than U.K. and Ireland	1,356		419		—		1,775
Asia Pacific	661		161		—		822
Total revenue	$	5,625	$	2,228	$	(23)	$	7,830

Schedule of Capitalized Contract Cost

An analysis of the changes in the net carrying amount of costs to fulfill contracts with customers are as follows (in millions):

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
Balance at beginning of period	$	302	$	269	$	424	$	370
Additions	409		386		827		766
Amortization	(448)		(390)		(992)		(868)
Impairment	—		—		—		—
Foreign currency translation and other	10		(1)		14		(4)
Balance at end of period	$	273	$	264	$	273	$	264

An analysis of the changes in the net carrying amount of costs to obtain contracts with customers are as follows (in millions):

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
Balance at beginning of period	$	208	$	194	$	207	$	195
Additions	14		18		27		32
Amortization	(40)		(14)		(53)		(27)
Impairment	—		—		—		—
Foreign currency translation and other	5		(2)		6		(4)
Balance at end of period	$	187	$	196	$	187	$	196