Segment Information (Tables)

3 Months Ended

Mar. 31, 2026

Segment Reporting [Abstract]

Schedule of Reportable Operating Segments, Consolidated Revenue and Segment Operating Income

The following tables include information about Aon’s reportable segments, including total segment revenue, total consolidated revenue, segment operating income, and income before income taxes:

	Three Months Ended March 31, 2026
(millions, except per share data)	Risk Capital			Human Capital			Corporate/Eliminations		Total Consolidated
Revenue
Total revenue (1)	$	3,502		$	1,539		$	(7)	$	5,034
Expenses
Compensation and benefits	1,632			759			2		2,393
Information technology	96			46			2		144
Premises	53			27			1		81
Other expenses (2)	339			264			98		701
Total operating expenses	2,120			1,096			103		3,319
Operating income	1,382			443			(110)		1,715
Operating margin	39.5		%	28.8		%			34.1		%
Non-operating expenses
Interest income									12
Interest expense									(179)
Other income (expense)									5
Income before income taxes									$	1,553

(1)Includes fiduciary investment income of $53 million in Risk Capital and $2 million in Human Capital for the three months ended March 31, 2026.

(2)Includes expenses related to Depreciation of fixed assets, Amortization and impairment of intangible assets, Accelerating Aon United Program expenses, and Other general expenses.

	Three Months Ended March 31, 2025
(millions, except per share data)	Risk Capital			Human Capital			Corporate/Eliminations		Total Consolidated
Revenue
Total revenue (1)	$	3,191		$	1,545		$	(7)	$	4,729
Expenses
Compensation and benefits	1,461			774			14		2,249
Information technology	90			45			1		136
Premises	52			29			1		82
Other expense (2)	391			294			116		801
Total operating expenses	1,994			1,142			132		3,268
Operating income	1,197			403			(139)		1,461
Operating margin	37.5		%	26.1		%			30.9		%
Non-operating expenses
Interest income									5
Interest expense									(206)
Other income (expense)									(10)
Income before income taxes									$	1,250

(1)Includes fiduciary investment income of $65 million in Risk Capital and $2 million in Human Capital for the three months ended March 31, 2025.

(2)Includes expenses related to Depreciation of fixed assets, Amortization and impairment of intangible assets, Accelerating Aon United Program expenses, and Other general expenses.