0000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 0000002 - Document - Audit Information link:presentationLink link:calculationLink link:definitionLink 9952151 - Statement - Consolidated Statements of Income link:presentationLink link:calculationLink link:definitionLink 9952152 - Statement - Consolidated Statements of Comprehensive Income link:presentationLink link:calculationLink link:definitionLink 9952153 - Statement - Consolidated Statements of Financial Position link:presentationLink link:calculationLink link:definitionLink 9952154 - Statement - Consolidated Statements of Financial Position (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952155 - Statement - Consolidated Statements of Shareholders’ Equity link:presentationLink link:calculationLink link:definitionLink 9952156 - Statement - Consolidated Statements of Shareholders’ Equity (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952157 - Statement - Consolidated Statements of Cash Flows link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - Basis of Presentation link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - Summary of Significant Accounting Principles and Practices link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - Revenue from Contracts with Customers link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - Accelerating Aon United Program link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - Other Financial Data link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - Acquisitions and Dispositions of Businesses link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - Goodwill and Other Intangible Assets link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - Debt link:presentationLink link:calculationLink link:definitionLink 9952166 - Disclosure - Lease Commitments link:presentationLink link:calculationLink link:definitionLink 9952167 - Disclosure - Income Taxes link:presentationLink link:calculationLink link:definitionLink 9952168 - Disclosure - Shareholders’ Equity link:presentationLink link:calculationLink link:definitionLink 9952169 - Disclosure - Employee Benefits link:presentationLink link:calculationLink link:definitionLink 9952170 - Disclosure - Share-Based Compensation Plans link:presentationLink link:calculationLink link:definitionLink 9952171 - Disclosure - Derivatives and Hedging link:presentationLink link:calculationLink link:definitionLink 9952172 - Disclosure - Fair Value Measurements and Financial Instruments link:presentationLink link:calculationLink link:definitionLink 9952173 - Disclosure - Claims, Lawsuits and Other Contingencies link:presentationLink link:calculationLink link:definitionLink 9952174 - Disclosure - Segment Information link:presentationLink link:calculationLink link:definitionLink 9955511 - Disclosure - Organization, Consolidation and Presentation of Financial Statements (Policies) link:presentationLink link:calculationLink link:definitionLink 9955512 - Disclosure - Summary of Significant Accounting Principles and Practices (Policies) link:presentationLink link:calculationLink link:definitionLink 9955513 - Disclosure - Summary of Significant Accounting Principles and Practices (Tables) link:presentationLink link:calculationLink link:definitionLink 9955514 - Disclosure - Revenue from Contracts with Customers (Tables) link:presentationLink link:calculationLink link:definitionLink 9955515 - Disclosure - Accelerating Aon United Program (Tables) link:presentationLink link:calculationLink link:definitionLink 9955516 - Disclosure - Other Financial Data (Tables) link:presentationLink link:calculationLink link:definitionLink 9955517 - Disclosure - Acquisitions and Dispositions of Businesses (Tables) link:presentationLink link:calculationLink link:definitionLink 9955518 - Disclosure - Goodwill and Other Intangible Assets (Tables) link:presentationLink link:calculationLink link:definitionLink 9955519 - Disclosure - Debt (Tables) link:presentationLink link:calculationLink link:definitionLink 9955520 - Disclosure - Lease Commitments (Tables) link:presentationLink link:calculationLink link:definitionLink 9955521 - Disclosure - Income Taxes (Tables) link:presentationLink link:calculationLink link:definitionLink 9955522 - Disclosure - Shareholders’ Equity (Tables) link:presentationLink link:calculationLink link:definitionLink 9955523 - Disclosure - Employee Benefits (Tables) link:presentationLink link:calculationLink link:definitionLink 9955524 - Disclosure - Share-Based Compensation Plans (Tables) link:presentationLink link:calculationLink link:definitionLink 9955525 - Disclosure - Derivatives and Hedging (Tables) link:presentationLink link:calculationLink link:definitionLink 9955526 - Disclosure - Fair Value Measurements and Financial Instruments (Tables) link:presentationLink link:calculationLink link:definitionLink 9955527 - Disclosure - Segment Information (Tables) link:presentationLink link:calculationLink link:definitionLink 9955528 - Disclosure - Summary of Significant Accounting Principles and Practices - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955529 - Disclosure - Summary of Significant Accounting Principles and Practices - Property, Plant and Equipment (Details) link:presentationLink link:calculationLink link:definitionLink 9955530 - Disclosure - Summary of Significant Accounting Principles and Practices - Intangible Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955531 - Disclosure - Revenue from Contracts with Customers - Disaggregation of Revenue (Details) link:presentationLink link:calculationLink link:definitionLink 9955532 - Disclosure - Revenue from Contracts with Customers - Contract Assets Rollforward (Details) link:presentationLink link:calculationLink link:definitionLink 9955533 - Disclosure - Accelerating Aon United Program - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955534 - Disclosure - Accelerating Aon United Program - Program Costs Incurred (Details) link:presentationLink link:calculationLink link:definitionLink 9955535 - Disclosure - Accelerating Aon United Program - Restructuring Liabilities for the Program (Details) link:presentationLink link:calculationLink link:definitionLink 9955536 - Disclosure - Other Financial Data - Schedule of Other Income (Expense) (Details) link:presentationLink link:calculationLink link:definitionLink 9955537 - Disclosure - Other Financial Data - Schedule of Allowance for Doubtful Accounts (Details) link:presentationLink link:calculationLink link:definitionLink 9955538 - Disclosure - Other Financial Data - Schedule of Other Current Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955539 - Disclosure - Other Financial Data - Components of Fixed Assets, Net (Details) link:presentationLink link:calculationLink link:definitionLink 9955540 - Disclosure - Other Financial Data - Schedule of Other Non-current Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955541 - Disclosure - Other Financial Data - Schedule of Other Current Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9955542 - Disclosure - Other Financial Data - Schedule of Other Non-current Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9955543 - Disclosure - Acquisitions and Dispositions of Businesses - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955544 - Disclosure - Acquisitions and Dispositions of Businesses - Schedule of Acquisitions (Details) link:presentationLink link:calculationLink link:definitionLink 9955545 - Disclosure - Acquisitions and Dispositions of Businesses - Schedule of Consideration Transferred and Preliminary Value of Intangible Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955546 - Disclosure - Acquisitions and Dispositions of Businesses - Schedule of Pro Forma Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955547 - Disclosure - Acquisitions and Dispositions of Businesses - Completed Dispositions (Details) link:presentationLink link:calculationLink link:definitionLink 9955548 - Disclosure - Acquisitions and Dispositions of Businesses - Other Significant Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9955549 - Disclosure - Goodwill and Other Intangible Assets - Schedule of Changes in the Net Carrying Amount of Goodwill (Details) link:presentationLink link:calculationLink link:definitionLink 9955550 - Disclosure - Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets by Asset Class (Details) link:presentationLink link:calculationLink link:definitionLink 9955551 - Disclosure - Goodwill and Other Intangible Assets - Schedule of Estimated Future Amortization Expense on Intangible Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955552 - Disclosure - Debt - Schedule of Outstanding Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9955553 - Disclosure - Debt - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955554 - Disclosure - Debt - Repayments of Long-Term Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9955555 - Disclosure - Debt - Schedule of Commercial Paper (Details) link:presentationLink link:calculationLink link:definitionLink 9955556 - Disclosure - Lease Commitments - Assets and Liabilities of Lessee (Details) link:presentationLink link:calculationLink link:definitionLink 9955557 - Disclosure - Lease Commitments - Lease Costs (Details) link:presentationLink link:calculationLink link:definitionLink 9955558 - Disclosure - Lease Commitments - Lease Terms and Assumptions (Details) link:presentationLink link:calculationLink link:definitionLink 9955559 - Disclosure - Lease Commitments - Cash Flow of Lessee (Details) link:presentationLink link:calculationLink link:definitionLink 9955560 - Disclosure - Lease Commitments - Lease Maturity (Details) link:presentationLink link:calculationLink link:definitionLink 9955560 - Disclosure - Lease Commitments - Lease Maturity (Details) link:presentationLink link:calculationLink link:definitionLink 9955561 - Disclosure - Income Taxes - Income from Continuing Operations Before Income Tax (Details) link:presentationLink link:calculationLink link:definitionLink 9955562 - Disclosure - Income Taxes - Schedule of Reconciliation of the Income Tax Provisions Based on its Domicile and Statutory Rate 2025 (Details) link:presentationLink link:calculationLink link:definitionLink 9955563 - Disclosure - Income Taxes - Schedule of Reconciliation Irish Statutory Corporate Tax Rate 2024 and 2023 (Details) link:presentationLink link:calculationLink link:definitionLink 9955564 - Disclosure - Income Taxes - Schedule of Cash Flow, Supplemental Disclosures (Details) link:presentationLink link:calculationLink link:definitionLink 9955565 - Disclosure - Income Taxes - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955566 - Disclosure - Income Taxes - Components of Aon's Deferred Tax Assets and Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9955567 - Disclosure - Income Taxes - Deferred Income Taxes (Assets and Liabilities Netted by Jurisdiction) as Classified in the Consolidated Statements of Financial Position (Details) link:presentationLink link:calculationLink link:definitionLink 9955568 - Disclosure - Income Taxes - Operating Loss Carryforwards (Details) link:presentationLink link:calculationLink link:definitionLink 9955569 - Disclosure - Income Taxes - Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Details) link:presentationLink link:calculationLink link:definitionLink 9955570 - Disclosure - Shareholders’ Equity - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955571 - Disclosure - Shareholders’ Equity - Schedule of Share Repurchases Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9955572 - Disclosure - Shareholders’ Equity - Schedule of Weighted Average Shares Outstanding (Details) link:presentationLink link:calculationLink link:definitionLink 9955573 - Disclosure - Shareholders’ Equity - Components of Accumulated Other Comprehensive Loss, Net of Related Tax (Details) link:presentationLink link:calculationLink link:definitionLink 9955574 - Disclosure - Employee Benefits - Schedule of Expense Recognized in Compensation and Benefit in the Consolidated Statements of Income (Details) link:presentationLink link:calculationLink link:definitionLink 9955575 - Disclosure - Employee Benefits - Pension Plans Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955576 - Disclosure - Employee Benefits - Reconciliation of the Changes in the Benefit Obligations and Fair Value of Assets and a Statement of the Funded Status (Details) link:presentationLink link:calculationLink link:definitionLink 9955577 - Disclosure - Employee Benefits - Amounts Recognized in the Consolidated Statements of Financial Position (Details) link:presentationLink link:calculationLink link:definitionLink 9955578 - Disclosure - Employee Benefits - Amounts Recognized in Accumulated Other Comprehensive Loss That Have Not Yet Been Recognized (Details) link:presentationLink link:calculationLink link:definitionLink 9955579 - Disclosure - Employee Benefits - Components of Net Periodic Benefit Cost (Details) link:presentationLink link:calculationLink link:definitionLink 9955580 - Disclosure - Employee Benefits - Weighted-Average Assumptions Used to Determine Future Benefit Obligations (Details) link:presentationLink link:calculationLink link:definitionLink 9955581 - Disclosure - Employee Benefits - Weighted-Average Assumptions Used to Determine the Net Periodic Benefit Cost (Details) link:presentationLink link:calculationLink link:definitionLink 9955582 - Disclosure - Employee Benefits - Expected Return on Plan Assets Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955583 - Disclosure - Employee Benefits - Schedule of Fair Value of U.S Plan Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955584 - Disclosure - Employee Benefits - Schedule of Fair Value of U.K. Plan Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955585 - Disclosure - Employee Benefits - Schedule of changes in Level 3 fair value for U.K. Pension Plans (Details) link:presentationLink link:calculationLink link:definitionLink 9955586 - Disclosure - Employee Benefits - Schedule of Fair Value of Other Plan Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955587 - Disclosure - Employee Benefits - Investment Policy and Strategy Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955588 - Disclosure - Employee Benefits - Cash Flows Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955589 - Disclosure - Employee Benefits - Estimated Future Benefit Payments (Details) link:presentationLink link:calculationLink link:definitionLink 9955590 - Disclosure - Employee Benefits - Overview of the Accumulated Benefit Obligation, Fair Value of Plan Assets, Funded Status and Net Amount (Details) link:presentationLink link:calculationLink link:definitionLink 9955591 - Disclosure - Employee Benefits - Schedule of Other Information Related to Company's Other Post-Retirement Plans (Details) link:presentationLink link:calculationLink link:definitionLink 9955592 - Disclosure - Employee Benefits - U.S. and Canadian Other Post-Retirement Benefits Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955593 - Disclosure - Share-Based Compensation Plans - Share-Based Compensation Expense Recognized in Continuing Operations (Details) link:presentationLink link:calculationLink link:definitionLink 9955594 - Disclosure - Share-Based Compensation Plans - Restricted Share Units Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955595 - Disclosure - Share-Based Compensation Plans - Summary of the Status of the Company's RSUs and PSAs (Details) link:presentationLink link:calculationLink link:definitionLink 9955596 - Disclosure - Share-Based Compensation Plans - Performance Share Awards Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955597 - Disclosure - Derivatives and Hedging - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955598 - Disclosure - Derivatives and Hedging - Notional and Fair Values of Derivative Instruments (Details) link:presentationLink link:calculationLink link:definitionLink 9955599 - Disclosure - Derivatives and Hedging - Schedule of Amounts of Derivative Gains (Losses) Recognized in the Consolidated Financial Statements (Details) link:presentationLink link:calculationLink link:definitionLink 9955600 - Disclosure - Fair Value Measurements and Financial Instruments - Schedule of Assets and Liabilities that are Measured at Fair Value on a Recurring Basis (Details) link:presentationLink link:calculationLink link:definitionLink 9955601 - Disclosure - Fair Value Measurements and Financial Instruments - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955602 - Disclosure - Fair Value Measurements and Financial Instruments - Schedule of Financial Instruments where the Carrying Amounts and Fair Values Differ (Details) link:presentationLink link:calculationLink link:definitionLink 9955603 - Disclosure - Claims, Lawsuits, and Other Contingencies - Legal Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955604 - Disclosure - Claims, Lawsuits, and Other Contingencies - Letters of Credit Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955605 - Disclosure - Claims, Lawsuits, and Other Contingencies - Guarantees and Indemnifications Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955606 - Disclosure - Segment Information - Schedule of Reportable Operating Segments, Consolidated Revenue and Segment Operating Income (Details) link:presentationLink link:calculationLink link:definitionLink 9955607 - Disclosure - Segment Information - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955608 - Disclosure - Segment Information - Schedule of Geographic Areas of Fixed Assets and Operating Lease Right-of-Use Asset (Details) link:presentationLink link:calculationLink link:definitionLink