0000001 - Document - COVER 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 BALANCE SHEETS link:presentationLink link:calculationLink link:definitionLink 9952154 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952155 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS link:presentationLink link:calculationLink link:definitionLink 9952156 - Statement - CONSOLIDATED STATEMENTS OF EQUITY link:presentationLink link:calculationLink link:definitionLink 9952157 - Disclosure - Nature of Operations link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - Principles of Consolidation and Other Matters link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - Revenue link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - Fiduciary Assets and Liabilities link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - Per Share Data link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - Supplemental Disclosures to the Consolidated Statements of Cash Flows link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - Other Comprehensive (Loss) Income link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - Acquisitions and Dispositions link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - Goodwill and Other Intangibles link:presentationLink link:calculationLink link:definitionLink 9952166 - Disclosure - Fair Value Measurements link:presentationLink link:calculationLink link:definitionLink 9952167 - Disclosure - Derivatives link:presentationLink link:calculationLink link:definitionLink 9952168 - Disclosure - Leases link:presentationLink link:calculationLink link:definitionLink 9952169 - Disclosure - Retirement Benefits link:presentationLink link:calculationLink link:definitionLink 9952170 - Disclosure - Debt link:presentationLink link:calculationLink link:definitionLink 9952171 - Disclosure - Restructuring Costs link:presentationLink link:calculationLink link:definitionLink 9952172 - Disclosure - Common Stock 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 9952175 - Disclosure - New Accounting Pronouncements link:presentationLink link:calculationLink link:definitionLink 9955511 - Disclosure - Principles of Consolidation and Other Matters (Policies) link:presentationLink link:calculationLink link:definitionLink 9955512 - Disclosure - Revenue (Tables) link:presentationLink link:calculationLink link:definitionLink 9955513 - Disclosure - Per Share Data (Tables) link:presentationLink link:calculationLink link:definitionLink 9955514 - Disclosure - Supplemental Disclosures to the Consolidated Statements of Cash Flows (Tables) link:presentationLink link:calculationLink link:definitionLink 9955515 - Disclosure - Other Comprehensive (Loss) Income (Tables) link:presentationLink link:calculationLink link:definitionLink 9955516 - Disclosure - Acquisitions and Dispositions (Tables) link:presentationLink link:calculationLink link:definitionLink 9955517 - Disclosure - Goodwill and Other Intangibles (Tables) link:presentationLink link:calculationLink link:definitionLink 9955518 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 9955519 - Disclosure - Leases (Tables) link:presentationLink link:calculationLink link:definitionLink 9955520 - Disclosure - Retirement Benefits (Tables) link:presentationLink link:calculationLink link:definitionLink 9955521 - Disclosure - Debt (Tables) link:presentationLink link:calculationLink link:definitionLink 9955522 - Disclosure - Restructuring Costs (Tables) link:presentationLink link:calculationLink link:definitionLink 9955523 - Disclosure - Segment Information (Tables) link:presentationLink link:calculationLink link:definitionLink 9955524 - Disclosure - Nature of Operations (Details) link:presentationLink link:calculationLink link:definitionLink 9955525 - Disclosure - Principles of Consolidation and Other Matters (Details) link:presentationLink link:calculationLink link:definitionLink 9955526 - Disclosure - Revenue (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955527 - Disclosure - Revenue (Disaggregation of Revenue) (Details) link:presentationLink link:calculationLink link:definitionLink 9955528 - Disclosure - Revenue (Contract Assets and Liabilities) (Details) link:presentationLink link:calculationLink link:definitionLink 9955529 - Disclosure - Fiduciary Assets and Liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 9955530 - Disclosure - Per Share Data (Details) link:presentationLink link:calculationLink link:definitionLink 9955531 - Disclosure - Supplemental Disclosures to the Consolidated Statements of Cash Flows (Supplemental Cash Flow Disclosures) (Details) link:presentationLink link:calculationLink link:definitionLink 9955532 - Disclosure - Supplemental Disclosures to the Consolidated Statements of Cash Flows (Supplemental Operating and Financing Cash Flow Items) (Details) link:presentationLink link:calculationLink link:definitionLink 9955533 - Disclosure - Supplemental Disclosures to the Consolidated Statements of Cash Flows (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955534 - Disclosure - Other Comprehensive (Loss) Income (Changes Net of Tax in the Balances of Each Components of Other Accumulated Comprehensive Income Loss) (Details) link:presentationLink link:calculationLink link:definitionLink 9955535 - Disclosure - Other Comprehensive (Loss) Income (Schedule of Other Comprehensive (Loss) Income (Details) link:presentationLink link:calculationLink link:definitionLink 9955536 - Disclosure - Acquisitions and Dispositions (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955537 - Disclosure - Acquisitions and Dispositions (Allocation of Acquisition Costs) (Details) link:presentationLink link:calculationLink link:definitionLink 9955538 - Disclosure - Acquisitions and Dispositions (Acquired Finite-Lived Intangible Assets by Major class) (Details) link:presentationLink link:calculationLink link:definitionLink 9955539 - Disclosure - Acquisitions and Dispositions (Pro-Forma Information) (Details) link:presentationLink link:calculationLink link:definitionLink 9955540 - Disclosure - Goodwill and Other Intangibles (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955541 - Disclosure - Goodwill and Other Intangibles (Changes in the Carrying Amount of Goodwill) (Details) link:presentationLink link:calculationLink link:definitionLink 9955542 - Disclosure - Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) link:presentationLink link:calculationLink link:definitionLink 9955543 - Disclosure - Goodwill and Other Intangibles (Estimated Future Aggregate Amortization Expense) (Details) link:presentationLink link:calculationLink link:definitionLink 9955544 - Disclosure - Fair Value Measurements (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955545 - Disclosure - Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) link:presentationLink link:calculationLink link:definitionLink 9955546 - Disclosure - Fair Value Measurements (Changes in Fair Value Of Level 3 Liabilities Representing Acquisition Related Contingent Consideration) (Details) link:presentationLink link:calculationLink link:definitionLink 9955547 - Disclosure - Derivatives (Details) link:presentationLink link:calculationLink link:definitionLink 9955548 - Disclosure - Leases (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955549 - Disclosure - Leases (Lease Cost and Additional Information) (Details) link:presentationLink link:calculationLink link:definitionLink 9955550 - Disclosure - Leases (Future Minimum Payments for Operating Leases) (Details) link:presentationLink link:calculationLink link:definitionLink 9955550 - Disclosure - Leases (Future Minimum Payments for Operating Leases) (Details) link:presentationLink link:calculationLink link:definitionLink 9955551 - Disclosure - Retirement Benefits (Weighted Average Actuarial Assumptions Utilized to Calculate the Net Periodic Benefit Costs) (Details) link:presentationLink link:calculationLink link:definitionLink 9955552 - Disclosure - Retirement Benefits (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955553 - Disclosure - Retirement Benefits (Defined Benefit Plan Net Periodic Benefit Cost Combined U.S. and Significant Non-U.S. Plans) (Details) link:presentationLink link:calculationLink link:definitionLink 9955554 - Disclosure - Retirement Benefits (Defined Benefit Plan Net Periodic Benefit Cost Amounts Recorded in Consolidated Statement of Income) (Details) link:presentationLink link:calculationLink link:definitionLink 9955555 - Disclosure - Debt (Outstanding Debt) (Details) link:presentationLink link:calculationLink link:definitionLink 9955556 - Disclosure - Debt (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955557 - Disclosure - Debt (Estimated Fair Value of Significant Financial Instruments) (Details) link:presentationLink link:calculationLink link:definitionLink 9955558 - Disclosure - Restructuring Costs (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955559 - Disclosure - Restructuring Costs (Restructuring and Related Costs Incurred) (Details) link:presentationLink link:calculationLink link:definitionLink 9955560 - Disclosure - Restructuring Costs (Restructuring Activities) (Details) link:presentationLink link:calculationLink link:definitionLink 9955561 - Disclosure - Common Stock (Details) link:presentationLink link:calculationLink link:definitionLink 9955562 - Disclosure - Claims, Lawsuits and Other Contingencies (Details) link:presentationLink link:calculationLink link:definitionLink 9955563 - Disclosure - Segment Information (Narrative) (Details) link:presentationLink link:calculationLink link:definitionLink 9955564 - Disclosure - Segment Information (Selected Information and Details for MMC's Operating Segments) (Details) link:presentationLink link:calculationLink link:definitionLink 9955565 - Disclosure - Segment Information (Details of Operating Segment Revenue) (Details) link:presentationLink link:calculationLink link:definitionLink