Goodwill and Other Intangibles (Tables)

12 Months Ended

Dec. 31, 2024

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes in the Carrying Amount of Goodwill

Changes in the carrying amount of goodwill are as follows: 

(In millions)	2024		2023
Balance at January 1,	$	17,231	$	16,251
Goodwill acquired (a)	6,407		813
Other adjustments (b)	(332)		167
Balance at December 31,	$	23,306	$	17,231

(a)Includes $5.2 billion from the acquisition of McGriff in 2024.

(b)Primarily reflects the impact of foreign exchange.

Schedule of Finite-lived Intangible Assets

The gross cost and accumulated amortization of other intangible assets at December 31, 2024 and 2023 are as follows:

(In millions)	2024						2023
	Gross Cost		Accumulated Amortization		Net Carrying Amount		Gross Cost		Accumulated Amortization		Net Carrying Amount
Customer relationships (a)	$	6,650	$	1,961	$	4,689	$	4,337	$	1,761	$	2,576
Other (a) (b)	476		345		131		391		337		54
Other intangible assets	$	7,126	$	2,306	$	4,820	$	4,728	$	2,098	$	2,630

(a)Customer relationships and Other include $2.1 billion and $60 million, respectively, from the acquisition of McGriff in 2024.

(b)Primarily non-compete agreements, trade names and developed technology.

Schedule of Estimated Future Aggregate Amortization Expense

The estimated future aggregate amortization expense is as follows:

For the Years Ended December 31,
(In millions)	Estimated Expense
2025	$	511
2026	488
2027	452
2028	431
2029	417
Subsequent years	2,521
Total future amortization	$	4,820