Income Taxes - Reconciliation of U.S. Federal Statutory Income Tax Rate to the Effective Tax Rate (Parenthetical) (Detail)	12 Months Ended
Dec. 31, 2021
Income Tax Disclosure [Abstract]
Percentage of Foreign Derived Intangible Income related to favorable impact on prior years from final regulations	(3.00%)

Percentage of Foreign Derived Intangible Income related to favorable impact on prior years from final regulations.

No definition available.

Name:	msci_PercentageOfForeignDerivedIntangibleIncomeRelatedToFavorableImpactOnPriorYearsFromFinalRegulations
Namespace Prefix:	msci_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration