XML 100 R7.htm IDEA: XBRL DOCUMENT
v3.20.1

Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions | Total | COMMON STOCK | ADDITIONAL PAID-IN CAPITAL | RETAINED EARNINGS | ACCUMULATED OTHER COMPREHENSIVE LOSS | TREASURY SHARES | NON-CONTROLLING INTERESTS
--- | --- | --- | --- | --- | --- | --- | ---
Balance, beginning of period at Dec. 31, 2018 |  | $ 561 | $ 817 | $ 14,347 | $ (4,647) | $ (3,567) | $ 73
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Change in accrued stock compensation costs |  |  | (101) |  |  |  |
Issuance of shares under stock compensation plans and employee stock purchase plans |  |  | (35) |  |  | 182 |
Other |  |  | 0 |  |  |  |
Net income attributable to the Company | $ 727 |  |  | 716 |  |  | 11
Dividend equivalents declared |  |  |  | (2) |  |  |
Dividends declared |  |  |  | (419) |  |  |
Other comprehensive loss, net of tax | 57 |  |  |  | 57 |  |
Net non-controlling interests disposed |  |  |  |  |  |  | 0
Distributions and other changes |  |  |  |  |  |  | (7)
Balance, end of period at Mar. 31, 2019 | $ 7,986 |  | 681 | 14,642 | (4,590) | (3,385) | 77
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Dividends declared per share (in dollars per share) | $ 0.83 |  |  |  |  |  |
Balance, beginning of period at Dec. 31, 2019 | $ 7,943 | $ 561 | 862 | 15,199 | (5,055) | (3,774) | 150
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Change in accrued stock compensation costs |  |  | (129) |  |  |  |
Issuance of shares under stock compensation plans and employee stock purchase plans |  |  | 14 |  |  | 119 |
Other |  |  | (1) |  |  |  |
Net income attributable to the Company | 767 |  |  | 754 |  |  | 13
Dividend equivalents declared |  |  |  | (4) |  |  |
Dividends declared |  |  |  | (459) |  |  |
Other comprehensive loss, net of tax | (792) |  |  |  | (792) |  |
Net non-controlling interests disposed |  |  |  |  |  |  | (3)
Distributions and other changes |  |  |  |  |  |  | (4)
Balance, end of period at Mar. 31, 2020 | $ 7,451 |  | $ 746 | $ 15,490 | $ (5,847) | $ (3,655) | $ 156
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Dividends declared per share (in dollars per share) | $ 0.91 |  |  |  |  |  |

X
- Definition Common Stock, Dividends Per Share, Cash, Declared + References No definition available. + Details
Name: | mmc_CommonStockDividendsPerShareCashDeclared
Namespace Prefix: | mmc_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Issued During Period, Value, Share-based Compensation and Employee Stock Purchase Plan, And Related Tax Deficiency + References No definition available. + Details
Name: | mmc_StockIssuedDuringPeriodValueSharebasedCompensationandEmployeeStockPurchasePlanAndRelatedTaxDeficiency
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of other increase (decrease) in additional paid in capital (APIC). + References No definition available. + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 20 -Section 55 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=118258462&loc=d3e11149-113907 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 20 -Section 55 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=118258462&loc=d3e11178-113907 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 35 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116855982&loc=d3e4534-113899 + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of paid and unpaid common stock dividends declared with the form of settlement in cash. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_DividendsCommonStockCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of paid and unpaid cash dividends declared for award under share-based payment arrangement. + References No definition available. + Details
Name: | us-gaap_DividendsShareBasedCompensationCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_IncreaseDecreaseInStockholdersEquityRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase in noncontrolling interest from a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684 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 (e)(1) -URI http://asc.fasb.org/extlink&oid=116869197&loc=d3e4845-128472 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 55 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=118951672&loc=d3e1436-108581 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4J -URI http://asc.fasb.org/extlink&oid=116874947&loc=SL4591551-111686 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3000-108585 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599 Reference 10: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4K -URI http://asc.fasb.org/extlink&oid=116874947&loc=SL4591552-111686 + Details
Name: | us-gaap_ProfitLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4568740-111683 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4I -URI http://asc.fasb.org/extlink&oid=116874947&loc=SL4590271-111686 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4568447-111683 + Details
Name: | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant