XML 70 R57.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Supplemental Disclosures to the Consolidated Statements of Cash Flows (Schedule of Analysis for Doubtful Accounts) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward] |  |  |
Balance at January 1, | $ 160 | $ 166 | $ 142
Provision charged to operations | 17 | 17 | 46
Accounts written-off, net of recoveries | (20) | (17) | (16)
Effect of exchange rate changes and other | (6) | (6) | (6)
Balance at December 31, | $ 151 | $ 160 | $ 166

X
- Definition Allowance For Doubtful Accounts Receivable, Effect Of Exchange Rate Changes And Other + References No definition available. + Details
Name: | mmc_AllowanceForDoubtfulAccountsReceivableEffectOfExchangeRateChangesAndOther
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Allowance For Doubtful Accounts Receivable, Write-offs, Net Of Recoveries + References No definition available. + Details
Name: | mmc_AllowanceForDoubtfulAccountsReceivableWriteoffsNetOfRecoveries
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of allowance for credit loss on accounts receivable, classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-4 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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_AllowanceForDoubtfulAccountsReceivableRollforward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense (reversal of expense) for expected credit loss on accounts receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_ProvisionForDoubtfulAccounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration