Long-Term Debt, Maturity, after Year Four

No definition available.

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Namespace Prefix:	mco_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04.(a))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in remainder of current fiscal year.

+ References

+ Details

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Indebtedness - Principal Payments Due on Long-Term Borrowings (Detail) - USD ($)			3 Months Ended	6 Months Ended
	May 20, 2020	Mar. 25, 2020	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
2020 (After June 30,)				$ 0
2021				500,000,000
2022				500,000,000
2023				500,000,000
2024				500,000,000
Thereafter				4,304,000,000
Total principal payment				6,304,000,000	$ 5,603,000,000
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
2022				500,000,000
Total principal payment				500,000,000	500,000,000
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
2024				500,000,000
Total principal payment				500,000,000	500,000,000
5.25% 2014 Senior Notes (30-Year), due 2044
Debt Instrument [Line Items]
Thereafter				600,000,000
Total principal payment				$ 600,000,000	600,000,000
Debt instrument, term			30 years	30 years
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Thereafter				$ 562,000,000
Total principal payment				562,000,000	561,000,000
2.75% 2017 Senior Notes, due 2021
Debt Instrument [Line Items]
2021				500,000,000
Total principal payment				500,000,000	500,000,000
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
2023				500,000,000
Total principal payment				500,000,000	500,000,000
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Thereafter				500,000,000
Total principal payment				500,000,000	500,000,000
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Thereafter				400,000,000
Total principal payment				400,000,000	400,000,000
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Thereafter				400,000,000
Total principal payment				400,000,000	400,000,000
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Thereafter				842,000,000
Total principal payment				842,000,000	$ 842,000,000
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
Thereafter				700,000,000
Total principal payment		$ 700,000,000		700,000,000
Debt instrument, term		5 years
3.25% 2020 Senior Notes, due 2050
Debt Instrument [Line Items]
Thereafter				300,000,000
Total principal payment	$ 300,000,000			$ 300,000,000
Debt instrument, term	30 years