v3.25.1
Employee Benefits (Tables)
 3 Months Ended
Mar. 31, 2025
Retirement Benefits [Abstract]  
Schedule of Components of Net Periodic Benefit Cost for the Pension Plans
The following table provides the components of the net periodic (benefit) cost recognized in the Condensed Consolidated Statements of Income for Aon’s significant U.K., U.S., and other major pension plans, which are located in the Netherlands and Canada. Service cost is reported in Compensation and benefits and all other components are reported in Other income (expense) as follows (in millions):
 Three Months Ended March 31,
 
U.K.
U.S.
Other
 202520242025202420252024
Service cost$— $— $— $— $— $— 
Interest cost37 35 26 23 9 9 
Expected return on plan assets, net of administration expenses(43)(47)(30)(33)(12)(13)
Amortization of prior-service cost1 1 — — — — 
Amortization of net actuarial loss22 20 9 7 3 3 
Net periodic cost (benefit) $17 $9 $5 $(3)$— $(1)
Schedule of Employer's Contributions The following table summarizes contributions made to the Company’s significant pension plans (in millions):
Three Months Ended March 31,
20252024
Contributions to U.K. pension plans
$1 $1 
Contributions to U.S. pension plans
27 14 
Contributions to other major pension plans2 2 
Total contributions$30 $17