v3.22.1

Commitments and Contingencies - Schedule of Interest Payments Due Attributable to Senior Notes (Detail)	3 Months Ended
	Mar. 31, 2022
4.000% Senior Unsecured Notes Due 2029 [Member]
Debt Instrument [Line Items]
First semi-annual interest payment date	--05-15
Second semi-annual interest payment date	--11-15
3.625% Senior Unsecured Notes Due 2030 [Member]
Debt Instrument [Line Items]
First semi-annual interest payment date	--03-01
Second semi-annual interest payment date	--09-01
3.875% Senior Unsecured Notes Due 2031 [Member]
Debt Instrument [Line Items]
First semi-annual interest payment date	--06-01
Second semi-annual interest payment date	--12-01
3.625% Senior Unsecured Notes Due 2031 [Member]
Debt Instrument [Line Items]
First semi-annual interest payment date	--05-01
Second semi-annual interest payment date	--11-01
3.250% Senior Unsecured Notes Due 2033 [Member]
Debt Instrument [Line Items]
First semi-annual interest payment date	--02-15
Second semi-annual interest payment date	--08-15

X

- Definition

First semi-annual interest payment date.

+ References

No definition available.

+ Details

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Namespace Prefix:	msci_
Data Type:	xbrli:gMonthDayItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Second semi-annual interest payment date.

+ References

No definition available.

+ Details

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Namespace Prefix:	msci_
Data Type:	xbrli:gMonthDayItemType
Balance Type:	na
Period Type:	duration

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

No definition available.

+ Details

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

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: