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v3.25.1

Accelerating Aon United Program - Schedule of Changes in the Company’s Liabilities for the Program (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
Restructuring Reserve [Roll Forward] |  |
Charges | $ 110 | $ 119
Accelerating Aon United Program |  |
Restructuring Reserve [Roll Forward] |  |
Liability balance as of December 31, 2024 | 114 |
Charges | 110 | $ 119
Cash payments | (97) |
Foreign currency translation and other | 0 |
Non-cash charges | (19) |
Liability balance as of March 31, 2025 | 108 |
Total costs incurred from inception to date | 634 |
Asset amortization | 2 |
Accelerating Aon United Program | Technology and other |  |
Restructuring Reserve [Roll Forward] |  |
Liability balance as of December 31, 2024 | 17 |
Charges | 56 |
Cash payments | (45) |
Foreign currency translation and other | 0 |
Non-cash charges | (2) |
Liability balance as of March 31, 2025 | 26 |
Total costs incurred from inception to date | 196 |
Accelerating Aon United Program | Workforce optimization |  |
Restructuring Reserve [Roll Forward] |  |
Liability balance as of December 31, 2024 | 97 |
Charges | 51 |
Cash payments | (52) |
Foreign currency translation and other | 0 |
Non-cash charges | (14) |
Liability balance as of March 31, 2025 | 82 |
Total costs incurred from inception to date | 351 |
Accelerating Aon United Program | Asset impairments |  |
Restructuring Reserve [Roll Forward] |  |
Liability balance as of December 31, 2024 | 0 |
Charges | 3 |
Cash payments | 0 |
Foreign currency translation and other | 0 |
Non-cash charges | (3) |
Liability balance as of March 31, 2025 | 0 |
Total costs incurred from inception to date | $ 87 |

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