v3.24.1.u1
Cover
Apr. 26, 2024
Cover [Abstract]  
Document Type 8-K
Document Period End Date Apr. 26, 2024
Entity Registrant Name Aon plc
Entity Incorporation, State or Country Code L2
Entity File Number 1-7933
Entity Tax Identification Number 98-1539969
Entity Address, Address Line One Metropolitan Building
Entity Address, Address Line Two James Joyce Street
Entity Address, City or Town Dublin 1
Entity Address, Country IE
Entity Address, Postal Zip Code D01 K0Y8
City Area Code 353 1
Local Phone Number 266 6000
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Document Information [Line Items]  
Entity Emerging Growth Company false
Amendment Flag false
Entity Central Index Key 0000315293
Class A Ordinary Shares $0.01 nominal value  
Document Information [Line Items]  
Title of 12(b) Security Class A Ordinary Shares $0.01 nominal value
Trading Symbol AON
Security Exchange Name NYSE
Guarantees of Aon plc’s 3.500% Senior Notes due 2024  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 3.500% Senior Notes due 2024
Trading Symbol AON24
Security Exchange Name NYSE
Guarantees of Aon plc’s 3.875% Senior Notes due 2025  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 3.875% Senior Notes due 2025
Trading Symbol AON25
Security Exchange Name NYSE
Guarantees of Aon plc’s 2.875% Senior Notes due 2026  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 2.875% Senior Notes due 2026
Trading Symbol AON26
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.850% Senior Notes due 2027  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.850% Senior Notes due 2027
Trading Symbol AON27
Security Exchange Name NYSE
Guarantees of Aon North America, Inc.'s 5.125% Senior Notes due 2027  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon North America, Inc.'s 5.125% Senior Notes due 2027
Trading Symbol AON27B
Security Exchange Name NYSE
Guarantees of Aon North America, Inc.'s 5.150% Senior Notes due 2029  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon North America, Inc.'s 5.150% Senior Notes due 2029
Trading Symbol AON29
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.050% Senior Notes due 2031  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.050% Senior Notes due 2031
Trading Symbol AON31
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.600% Senior Notes due 2031  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdingsplc’s 2.600% Senior Notes due 2031
Trading Symbol AON31A
Security Exchange Name NYSE
Guarantees of Aon North America, Inc.'s 5.300% Senior Notes due 2031  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon North America, Inc.'s 5.300% Senior Notes due 2031
Trading Symbol AON31B
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc’s 5.000% Senior Notes due 2032  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdingsplc’s 5.000% Senior Notes due 2032
Trading Symbol AON32
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc's 5.350% Senior Notes due 2033  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdings plc's 5.350% Senior Notes due 2033
Trading Symbol AON33
Security Exchange Name NYSE
Guarantees of Aon North America, Inc.'s 5.450% Senior Notes due 2034  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon North America, Inc.'s 5.450% Senior Notes due 2034
Trading Symbol AON34
Security Exchange Name NYSE
Guarantees of Aon plc’s 4.250% Senior Notes due 2042  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 4.250% Senior Notes due 2042
Trading Symbol AON42
Security Exchange Name NYSE
Guarantees of Aon plc’s 4.450% Senior Notes due 2043  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 4.450% Senior Notes due 2043
Trading Symbol AON43
Security Exchange Name NYSE
Guarantees of Aon plc’s 4.600% Senior Notes due 2044  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 4.600% Senior Notes due 2044
Trading Symbol AON44
Security Exchange Name NYSE
Guarantees of Aon plc’s 4.750% Senior Notes due 2045  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon plc’s 4.750% Senior Notes due 2045
Trading Symbol AON45
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.900% Senior Notes due 2051  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.900% Senior Notes due 2051
Trading Symbol AON51
Security Exchange Name NYSE
Guarantees of Aon Corporation and Aon Global Holdings plc’s 3.900% Senior Notes due 2052  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon Corporation and Aon Global Holdingsplc’s 3.900% Senior Notes due 2052
Trading Symbol AON52
Security Exchange Name NYSE
Guarantees of Aon North America, Inc.'s 5.750% Senior Notes due 2054  
Document Information [Line Items]  
Title of 12(b) Security Guarantees of Aon North America, Inc.'s 5.750% Senior Notes due 2054
Trading Symbol AON54
Security Exchange Name NYSE