XML 29 R43.htm IDEA: XBRL DOCUMENT v2.4.1.9
Summary of Marketable Securities by Asset Type (Detail) (USD $)
In Thousands, unless otherwise specified
Nov. 30, 2014
May 31, 2014
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost $ 125,872us-gaap_AvailableForSaleSecuritiesAmortizedCost $ 129,660us-gaap_AvailableForSaleSecuritiesAmortizedCost
Available-for-Sale Securities, Gross Unrealized Gains 11,247us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax 14,645us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Available-for-Sale Securities, Gross Unrealized Losses (1,916)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax (1,425)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 135,203us-gaap_AvailableForSaleSecurities 142,880us-gaap_AvailableForSaleSecurities
Equity securities    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 104,737us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember		 106,838us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
Available-for-Sale Securities, Gross Unrealized Gains 10,856us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember		 14,223us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
Available-for-Sale Securities, Gross Unrealized Losses (1,681)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember		 (1,261)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 113,912us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember		 119,800us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
Equity securities | Stocks | Foreign    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 1,829us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 984us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Available-for-Sale Securities, Gross Unrealized Gains 297us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 669us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Available-for-Sale Securities, Gross Unrealized Losses (27)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 (20)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 2,099us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 1,633us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Equity securities | Stocks | Domestic    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 27,810us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 31,071us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Available-for-Sale Securities, Gross Unrealized Gains 7,751us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 8,965us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Available-for-Sale Securities, Gross Unrealized Losses (76)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 (132)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 35,485us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember		 39,904us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommonStockMember
Equity securities | Mutual funds | Foreign    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 31,523us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 30,541us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Available-for-Sale Securities, Gross Unrealized Gains 2,321us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 2,799us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 33,844us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 33,340us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_ForeignMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Equity securities | Mutual funds | Domestic    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 43,575us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 44,242us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Available-for-Sale Securities, Gross Unrealized Gains 487us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 1,790us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Available-for-Sale Securities, Gross Unrealized Losses (1,578)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 (1,109)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 42,484us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember		 44,923us-gaap_AvailableForSaleSecurities
/ invest_InvestmentGeographicRegionAxis
= rpm_DomesticMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_MutualFundsMember
Fixed maturity    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 21,135us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember		 22,822us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
Available-for-Sale Securities, Gross Unrealized Gains 391us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember		 422us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
Available-for-Sale Securities, Gross Unrealized Losses (235)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember		 (164)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 21,291us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember		 23,080us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
Fixed maturity | U.S. Treasury and other government    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 19,615us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 21,156us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Available-for-Sale Securities, Gross Unrealized Gains 136us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 152us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Available-for-Sale Securities, Gross Unrealized Losses (231)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 (164)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 19,520us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 21,144us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Fixed maturity | Corporate bonds    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 1,399us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember		 1,544us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember
Available-for-Sale Securities, Gross Unrealized Gains 202us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember		 212us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember
Available-for-Sale Securities, Gross Unrealized Losses (4)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember		  
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 1,597us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember		 1,756us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateBondSecuritiesMember
Fixed maturity | Foreign bonds    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 38us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_ForeignGovernmentBondsMember		 37us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_ForeignGovernmentBondsMember
Available-for-Sale Securities, Gross Unrealized Gains 1us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_ForeignGovernmentBondsMember		 3us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_ForeignGovernmentBondsMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) 39us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_ForeignGovernmentBondsMember		 40us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= rpm_ForeignGovernmentBondsMember
Fixed maturity | Mortgage-backed securities    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-Sale Securities, Amortized Cost 83us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesMember		 85us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesMember
Available-for-Sale Securities, Gross Unrealized Gains 52us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesMember		 55us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesMember
Available-for-Sale Securities, Fair Value (Net Carrying Amount) $ 135us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesMember		 $ 140us-gaap_AvailableForSaleSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedIncomeSecuritiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesMember