Label	Element	Value
Partners' Capital Account, Unit-based Compensation	us-gaap_PartnersCapitalAccountUnitBasedCompensation	$ 105,922,000
Adjustments to Additional Paid in Capital Initial Establishment of Deferred Tax Assets Net of Amounts Payable under Tax Receivable Agreement	mc_AdjustmentsToAdditionalPaidInCapitalInitialEstablishmentOfDeferredTaxAssetsNetOfAmountsPayableUnderTaxReceivableAgreement	10,854,000
Adjustments to Additional Paid in Capital Tax Benefit Related to Appreciation Units	mc_AdjustmentsToAdditionalPaidInCapitalTaxBenefitRelatedToAppreciationUnits	4,308,000
Adjustments to Additional Paid in Capital Increase in Deferred Tax Asset Related to Initial Public Offering	mc_AdjustmentsToAdditionalPaidInCapitalIncreaseInDeferredTaxAssetRelatedToInitialPublicOffering	1,302,000
Exchange Of Partnership Units To Common Stock In Connection With Secondary Offering Value	mc_ExchangeOfPartnershipUnitsToCommonStockInConnectionWithSecondaryOfferingValue	20,711,000
Adjustments to Additional Paid in Capital Distributions to Partners of Parent	mc_AdjustmentsToAdditionalPaidInCapitalDistributionsToPartnersOfParent	139,429,000
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	(2,638,000)
Dividends	us-gaap_Dividends	76,233,000
Equity Based Contributions to Joint Venture and Global Advisory Board	mc_EquityBasedContributionsToJointVentureAndGlobalAdvisoryBoard	5,972,000
Stockholders' Equity, Other	us-gaap_StockholdersEquityOther	2,130,000
Retained Earnings [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	(3,012,000)
Dividends	us-gaap_Dividends	21,106,000
Accumulated Other Comprehensive Income [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	(842,000)
Additional Paid In Capital [Member]
Partners' Capital Account, Unit-based Compensation	us-gaap_PartnersCapitalAccountUnitBasedCompensation	39,156,000
Adjustments to Additional Paid in Capital Initial Establishment of Deferred Tax Assets Net of Amounts Payable under Tax Receivable Agreement	mc_AdjustmentsToAdditionalPaidInCapitalInitialEstablishmentOfDeferredTaxAssetsNetOfAmountsPayableUnderTaxReceivableAgreement	10,854,000
Adjustments to Additional Paid in Capital Tax Benefit Related to Appreciation Units	mc_AdjustmentsToAdditionalPaidInCapitalTaxBenefitRelatedToAppreciationUnits	4,308,000
Adjustments to Additional Paid in Capital Increase in Deferred Tax Asset Related to Initial Public Offering	mc_AdjustmentsToAdditionalPaidInCapitalIncreaseInDeferredTaxAssetRelatedToInitialPublicOffering	1,302,000
Exchange Of Partnership Units To Common Stock In Connection With Secondary Offering Value	mc_ExchangeOfPartnershipUnitsToCommonStockInConnectionWithSecondaryOfferingValue	33,723,000
Adjustments to Additional Paid in Capital Distributions to Partners of Parent	mc_AdjustmentsToAdditionalPaidInCapitalDistributionsToPartnersOfParent	139,429,000
Dividends	us-gaap_Dividends	(3,115,000)
Equity Based Contributions to Joint Venture and Global Advisory Board	mc_EquityBasedContributionsToJointVentureAndGlobalAdvisoryBoard	5,849,000
Stock Issued During Period, Value, New Issues	us-gaap_StockIssuedDuringPeriodValueNewIssues	162,032,000
Stockholders' Equity, Other	us-gaap_StockholdersEquityOther	(112,000)
Noncontrolling Interest [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	us-gaap_ProfitLoss	5,799,000
Partners' Capital Account, Unit-based Compensation	us-gaap_PartnersCapitalAccountUnitBasedCompensation	66,765,000
Exchange Of Partnership Units To Common Stock In Connection With Secondary Offering Value	mc_ExchangeOfPartnershipUnitsToCommonStockInConnectionWithSecondaryOfferingValue	(13,012,000)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	(1,796,000)
Dividends	us-gaap_Dividends	58,242,000
Equity Based Contributions to Joint Venture and Global Advisory Board	mc_EquityBasedContributionsToJointVentureAndGlobalAdvisoryBoard	123,000
Stockholders' Equity, Other	us-gaap_StockholdersEquityOther	$ 2,241,000
Common Class A [Member]
Stockholders' Equity, Other Shares	us-gaap_StockholdersEquityOtherShares	180
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation	76,722
Partners' Capital Account, Unit-based Compensation	us-gaap_PartnersCapitalAccountUnitBasedCompensation	$ 1,000
Exchange Of Partnership Units To Common Stock In Connection With Secondary Offering Value	mc_ExchangeOfPartnershipUnitsToCommonStockInConnectionWithSecondaryOfferingValue	$ 45,000
Common Class B [Member]
Stockholders' Equity, Other Shares	us-gaap_StockholdersEquityOtherShares	29,703
Exchange Of Partnership Units To Common Stock In Connection With Secondary Offering Value	mc_ExchangeOfPartnershipUnitsToCommonStockInConnectionWithSecondaryOfferingValue	$ (45,000)
Stockholders' Equity, Other	us-gaap_StockholdersEquityOther	$ 1,000