XML 65 R52.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Revenue - Change in Contract Assets and Liabilities (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022
Contract Assets |  |
Balance at January 1, | $ 335 | $ 290
Additions | 825 | 661
Transfers to accounts receivable | (805) | (614)
Effect of foreign exchange rate changes | 2 | (2)
Balance at December 31, | 357 | 335
Contract Liabilities |  |
Balance at January 1, | 837 | 776
Cash received for performance obligations not yet fulfilled | 822 | 726
Revenue recognized | (799) | (640)
Effect of foreign exchange rate changes | 9 | (25)
Balance at December 31, | $ 869 | $ 837

X
- Definition Contract with Customer, Asset, Effect of Foreign Exchange Rate Changes + References No definition available. + Details
Name: | mmc_ContractWithCustomerAssetEffectOfForeignExchangeRateChanges
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Contract with Customer, Liability, Effect of Foreign Exchange Rate Changes + References No definition available. + Details
Name: | mmc_ContractWithCustomerLiabilityEffectOfForeignExchangeRateChanges
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Contract with Customer, Liability, Increase (Decrease) for Cash Received for Performance Obligations Not Yet Fulfilled + References No definition available. + Details
Name: | mmc_ContractwithCustomerLiabilityIncreaseDecreaseforCashReceivedforPerformanceObligationsNotYetFulfilled
Namespace Prefix: | mmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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

X
- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-10 + Details
Name: | us-gaap_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInMeasureOfProgress
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, before allowance for credit loss, of right to consideration in exchange for good or service transferred to customer, when right is conditioned on something other than passage of time. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-14 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 7A -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-7A Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479837/606-10-45-1 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479837/606-10-45-3 + Details
Name: | us-gaap_ContractWithCustomerAssetGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of decrease in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time from transfer to receivable due to right to consideration becoming unconditional. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-10 + Details
Name: | us-gaap_ContractWithCustomerAssetReclassifiedToReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479837/606-10-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-8 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479837/606-10-45-2 + Details
Name: | us-gaap_ContractWithCustomerLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-8 + Details
Name: | us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration