XML 162 R114.htm IDEA: XBRL DOCUMENT
v3.19.2

Weighted-Average Assumptions used to Determine Benefit Obligations and Net Periodic Postretirement Cost (Detail) - Postretirement Benefits | 12 Months Ended
--- | ---
May 31, 2019 | May 31, 2018 | May 31, 2017
Domestic |  |  |
Health Care Cost Trend Rates Assumptions [Line Items] |  |  |
Year-End Benefit Obligations, Discount rate | 3.44% | 4.03% |
Year-End Benefit Obligations, Current healthcare cost trend rate | 7.29% | 7.86% |
Year-End Benefit Obligations, Ultimate healthcare cost trend rate | 4.36% | 4.36% |
Year-End Benefit Obligation, Year ultimate healthcare cost trend rate will be realized | 2037 | 2037 |
Net Periodic Postretirement Cost, Discount rate | 4.03% | 3.61% | 3.76%
Net Periodic Postretirement Cost, Healthcare cost trend rate | 7.86% | 14.75% | 10.37%
Net Periodic Postretirement Cost, Ultimate healthcare cost trend rate | 4.36% | 4.36% | 4.36%
Net Periodic Postretirement Cost, Year ultimate healthcare cost trend rate will be realized | 2037 | 2037 | 2037
Non-U.S. Plans |  |  |
Health Care Cost Trend Rates Assumptions [Line Items] |  |  |
Year-End Benefit Obligations, Discount rate | 3.22% | 3.70% |
Year-End Benefit Obligations, Current healthcare cost trend rate | 5.77% | 6.02% |
Year-End Benefit Obligations, Ultimate healthcare cost trend rate | 3.70% | 4.20% |
Year-End Benefit Obligation, Year ultimate healthcare cost trend rate will be realized | 2040 | 2032 |
Net Periodic Postretirement Cost, Discount rate | 3.70% | 3.61% | 3.92%
Net Periodic Postretirement Cost, Healthcare cost trend rate | 6.02% | 5.85% | 5.98%
Net Periodic Postretirement Cost, Ultimate healthcare cost trend rate | 4.20% | 4.20% | 4.20%
Net Periodic Postretirement Cost, Year ultimate healthcare cost trend rate will be realized | 2032 | 2030 | 2030

X
- Definition Defined Benefit Plan, Benefit Obligation, Current Health Care Cost Trend Rate + References No definition available. + Details
Name: | rpm_DefinedBenefitPlanBenefitObligationCurrentHealthCareCostTrendRate
Namespace Prefix: | rpm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Benefit Obligation, Ultimate Health Care Cost Trend Rate + References No definition available. + Details
Name: | rpm_DefinedBenefitPlanBenefitObligationUltimateHealthCareCostTrendRate
Namespace Prefix: | rpm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Ultimate Health Care Cost Trend Rate, Net Periodic Postretirement Benefit Cost + References No definition available. + Details
Name: | rpm_DefinedBenefitPlanUltimateHealthCareCostTrendRateNetPeriodicPostretirementBenefitCost
Namespace Prefix: | rpm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined benefit plan year ultimate healthcare realized cost trend rate. + References No definition available. + Details
Name: | rpm_DefinedBenefitPlanYearUltimateHealthcareRealizedCostTrendRate
Namespace Prefix: | rpm_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Health Care Cost Trend Rate used to Determine Net Period Benefit Cost + References No definition available. + Details
Name: | rpm_HealthCareCostTrendRateUsedToDetermineNetPeriodBenefitCost
Namespace Prefix: | rpm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Health Care Cost Trend Rates Assumptions [Line Items] + References No definition available. + Details
Name: | rpm_HealthCareCostTrendRatesAssumptionsLineItems
Namespace Prefix: | rpm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Year ultimate health care cost trend rate is expected to be reached, in CCYY format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate
Namespace Prefix: | us-gaap_
Data Type: | us-types:gYearListItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanSponsorLocationAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanSponsorLocationAxis=us-gaap_ForeignPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |