XML 133 R64.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Derivative Instruments And Hedging Activities - Schedule of Notional Amount of Net Investment Hedges (Detail) - Cross currency swaps € in Millions, $ in Millions | Mar. 31, 2024 USD ($) | Mar. 31, 2024 EUR (€) | Dec. 31, 2023 USD ($) | Dec. 31, 2023 EUR (€)
--- | --- | --- | --- | ---
Net Investment Hedging | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | € 2,903 |  | € 2,903
Net Investment Hedging | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | $ 3,050 |  | $ 3,050 |
Net Investment Hedging | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | 2,903 |  |
Net Investment Hedging | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | 3,050 |  |  |
2026 | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | 450 |  |
2026 | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | 500 |  |  |
2027 | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | 531 |  |
2027 | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | 550 |  |  |
2028 | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | 588 |  |
2028 | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | 600 |  |  |
2029 | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | 373 |  |
2029 | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | 400 |  |  |
2031 | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | 481 |  |
2031 | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | 500 |  |  |
2032 | Designated as Hedging Instrument | Currency Paid |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | € |  | € 480 |  |
2032 | Designated as Hedging Instrument | Currency Received |  |  |  |
Derivative [Line Items] |  |  |  |
Notional Amount | $ | $ 500 |  |  |

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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_NetInvestmentHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CurrencySwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TransactionTypeAxis=mco_CurrencyPaidMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TransactionTypeAxis=mco_CurrencyReceivedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=mco_NetInvestmentHedgingSettlementYear2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=mco_NetInvestmentHedgingSettlementYear2027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=mco_NetInvestmentHedgingSettlementYear2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=mco_NetInvestmentHedgingSettlementYear2029Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=mco_NetInvestmentHedgingSettlementYear2031Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=mco_NetInvestmentHedgingSettlementYear2032Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |