Consolidation, Noncontrolling Interests and Basis of Presentation - Additional Information (Detail)	Aug. 31, 2020
Accounting Policies [Abstract]
Percentage of controlled subsidiary's earnings	100.00%

Percentage of subsidiary earnings included in consolidation.

No definition available.

Name:	rpm_PercentageOfSubsidiaryEarningsIncludedInConsolidation
Namespace Prefix:	rpm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant