XML 27 R8.htm IDEA: XBRL DOCUMENT
v3.19.2

Nature of Operations | 6 Months Ended
--- | ---
Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract] |
Nature of Operations | Nature of Operations Marsh & McLennan Companies, Inc. and its consolidated subsidiaries (the "Company"), a global professional services firm, is organized based on the different services that it offers. Under this structure, the Company’s two segments are Risk and Insurance Services and Consulting. The Risk and Insurance Services ("RIS") segment provides risk management solutions, services, advice and insurance broking, reinsurance broking and insurance program management services for businesses, public entities, insurance companies, associations, professional services organizations, and private clients. The Company conducts business in this segment through Marsh and Guy Carpenter. The Company conducts business in its Consulting segment through Mercer and Oliver Wyman. Mercer provides consulting expertise, advice, services and solutions in the areas of health, wealth and career consulting services and products. Oliver Wyman provides specialized management and economic and brand consulting services. On April 1, 2019, the Company completed its previously announced acquisition (the "Transaction") of all of the outstanding shares of Jardine Lloyd Thompson Group plc ("JLT"), a public company organized under the laws of England and Wales. JLT results of operations for the three months ended June 30, 2019 are included in the Company’s results of operations for the second quarter of 2019. Prior periods in 2018 do not reflect JLT’s results of operations and therefore may affect comparability. Prior to being acquired by the Company, JLT operated in three segments: Specialty, Reinsurance and Employee Benefits. JLT operated in 41 countries, with significant revenue in the United Kingdom, Pacific, Asia and the United States. As of April 1, 2019, the historical JLT businesses were combined into MMC operations as follows: JLT Specialty was included by geography within Marsh, JLT Reinsurance was included in Guy Carpenter and the majority of JLT's Employee Benefits business was included in Mercer Health and Wealth.

X
- Definition The entire disclosure for the nature of an entity's business, major products or services, principal markets including location, and the relative importance of its operations in each business and the basis for the determination, including but not limited to, assets, revenues, or earnings. For an entity that has not commenced principal operations, disclosures about the risks and uncertainties related to the activities in which the entity is currently engaged and an understanding of what those activities are being directed toward. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -URI http://asc.fasb.org/topic&trid=2134479 + Details
Name: | us-gaap_NatureOfOperations
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration