XML 72 R53.htm IDEA: XBRL DOCUMENT
v3.19.2

Acquisitions and Dispositions (Allocation Of Acquisition Costs) (Details) $ in Millions, £ in Billions |  | 6 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 20, 2018 GBP (£) | Jun. 30, 2019 USD ($) | Jun. 30, 2018 USD ($) | Apr. 01, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |
Cash |  | $ 5,859 | $ 160 |  |  |
Estimated fair value of deferred/contingent consideration |  | 66 | 32 |  |  |
Total consideration |  | 5,925 | 192 |  |  |
Allocation of purchase price: |  |  |  |  |  |
Goodwill |  | 14,479 | $ 9,177 |  | $ 9,599 | $ 9,089
Jardine Lloyd Thompson Group plc |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Cash |  | 5,568 |  |  |  |
Estimated fair value of deferred/contingent consideration |  | 0 |  |  |  |
Total consideration | £ 5.2 | 5,568 |  |  |  |
Allocation of purchase price: |  |  |  |  |  |
Cash and cash equivalents |  | 353 |  |  |  |
Accounts receivable, net |  | 714 |  |  |  |
Other current assets |  | 143 |  |  |  |
Fixed assets, net |  | 81 |  |  |  |
Other intangible assets |  | 1,662 |  |  |  |
Goodwill |  | 4,695 |  |  |  |
Right of use assets |  | 379 |  |  |  |
Deferred tax assets |  | 57 |  |  |  |
Other assets |  | 503 |  |  |  |
Total assets acquired |  | 8,587 |  |  |  |
Current liabilities |  | 699 |  |  |  |
Fiduciary liabilities |  | 1,275 |  |  |  |
Less – cash and investments held in a fiduciary capacity |  | (1,275) |  |  |  |
Long-term debt |  | 1,044 |  | $ 1,000 |  |
Long-term lease liabilities |  | 386 |  |  |  |
Pension, post-retirement and post-employment liabilities |  | 234 |  |  |  |
Liabilities for errors and omissions |  | 31 |  |  |  |
Other liabilities |  | 316 |  |  |  |
Total liabilities assumed |  | 2,710 |  |  |  |
Non-controlling interests |  | 309 |  |  |  |
Net assets acquired |  | 5,568 |  |  |  |
Other |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Cash |  | 291 |  |  |  |
Estimated fair value of deferred/contingent consideration |  | 66 |  |  |  |
Total consideration |  | 357 |  |  |  |
Allocation of purchase price: |  |  |  |  |  |
Cash and cash equivalents |  | 6 |  |  |  |
Accounts receivable, net |  | 6 |  |  |  |
Other current assets |  | 0 |  |  |  |
Fixed assets, net |  | 2 |  |  |  |
Other intangible assets |  | 143 |  |  |  |
Goodwill |  | 200 |  |  |  |
Right of use assets |  | 0 |  |  |  |
Deferred tax assets |  | 0 |  |  |  |
Other assets |  | 8 |  |  |  |
Total assets acquired |  | 365 |  |  |  |
Current liabilities |  | 5 |  |  |  |
Fiduciary liabilities |  | 0 |  |  |  |
Less – cash and investments held in a fiduciary capacity |  | 0 |  |  |  |
Long-term debt |  | 0 |  |  |  |
Long-term lease liabilities |  | 0 |  |  |  |
Pension, post-retirement and post-employment liabilities |  | 0 |  |  |  |
Liabilities for errors and omissions |  | 0 |  |  |  |
Other liabilities |  | 3 |  |  |  |
Total liabilities assumed |  | 8 |  |  |  |
Non-controlling interests |  | 0 |  |  |  |
Net assets acquired |  | 357 |  |  |  |
Current Fiscal Period Acquisitions |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Cash |  | 5,859 |  |  |  |
Estimated fair value of deferred/contingent consideration |  | 66 |  |  |  |
Total consideration |  | 5,925 |  |  |  |
Allocation of purchase price: |  |  |  |  |  |
Cash and cash equivalents |  | 359 |  |  |  |
Accounts receivable, net |  | 720 |  |  |  |
Other current assets |  | 143 |  |  |  |
Fixed assets, net |  | 83 |  |  |  |
Other intangible assets |  | 1,805 |  |  |  |
Goodwill |  | 4,895 |  |  |  |
Right of use assets |  | 379 |  |  |  |
Deferred tax assets |  | 57 |  |  |  |
Other assets |  | 511 |  |  |  |
Total assets acquired |  | 8,952 |  |  |  |
Current liabilities |  | 704 |  |  |  |
Fiduciary liabilities |  | 1,275 |  |  |  |
Less – cash and investments held in a fiduciary capacity |  | (1,275) |  |  |  |
Long-term debt |  | 1,044 |  |  |  |
Long-term lease liabilities |  | 386 |  |  |  |
Pension, post-retirement and post-employment liabilities |  | 234 |  |  |  |
Liabilities for errors and omissions |  | 31 |  |  |  |
Other liabilities |  | 319 |  |  |  |
Total liabilities assumed |  | 2,718 |  |  |  |
Non-controlling interests |  | 309 |  |  |  |
Net assets acquired |  | $ 5,925 |  |  |  |

X
- Definition Business Combination, Contingent and Deferred Consideration + References No definition available. + Details
Name: | mmc_BusinessCombinationContingentandDeferredConsideration
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Including Goodwill + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedAssetsIncludingGoodwill
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Investments Held in Fiduciary Capacity, Noncurrent + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCashandInvestmentsHeldinFiduciaryCapacityNoncurrent
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fiduciary Liabilities, Gross, Noncurrent + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedFiduciaryLiabilitiesGrossNoncurrent
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liability, Defined Benefit Plan, Noncurrent + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedLiabilityDefinedBenefitPlanNoncurrent
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liability For Errors And Omissions + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedLiabilityForErrorsAndOmissions
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Liability, Noncurrent + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedOperatingLeaseLiabilityNoncurrent
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Right-of-Use Asset + References No definition available. + Details
Name: | mmc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedOperatingLeaseRightofUseAsset
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6613-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6578-128477 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of other assets expected to be realized or consumed before one year or the normal operating cycle, if longer, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax asset attributable to deductible temporary differences and carryforwards acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e31917-109318 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of intangible assets, excluding goodwill, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of liabilities assumed at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of property, plant, and equipment recognized as of the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=108330185&loc=d3e2207-128464 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount recognized as of the acquisition date for the assets, including goodwill, in excess of (less than) the aggregate liabilities assumed, less the noncontrolling interest in the acquiree. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mmc_JardineLloydThompsonGroupplcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mmc_OtherAcquisitionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mmc_CurrentFiscalPeriodAcquisitionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |