XML 43 R35.htm IDEA: XBRL DOCUMENT v2.4.1.9
Investment (Income), Net (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 6 Months Ended
Nov. 30, 2014
Nov. 30, 2013
Nov. 30, 2014
Nov. 30, 2013
Net Investment Income [Line Items]        
Interest (income) $ (1,601)us-gaap_InvestmentIncomeInterest $ (1,641)us-gaap_InvestmentIncomeInterest $ (3,005)us-gaap_InvestmentIncomeInterest $ (3,144)us-gaap_InvestmentIncomeInterest
(Gain) on sale of marketable securities (3,204)us-gaap_GainLossOnSaleOfSecuritiesNet (227)us-gaap_GainLossOnSaleOfSecuritiesNet (5,320)us-gaap_GainLossOnSaleOfSecuritiesNet (2,424)us-gaap_GainLossOnSaleOfSecuritiesNet
Other-than-temporary impairment on securities   111us-gaap_MarketableSecuritiesRealizedGainLossOtherThanTemporaryImpairmentsAmount   162us-gaap_MarketableSecuritiesRealizedGainLossOtherThanTemporaryImpairmentsAmount
Dividend (income) (253)us-gaap_InvestmentIncomeDividend (248)us-gaap_InvestmentIncomeDividend (536)us-gaap_InvestmentIncomeDividend (493)us-gaap_InvestmentIncomeDividend
Investment (income), net $ (5,058)rpm_NetInvestmentIncomeAndOtherIncome $ (2,005)rpm_NetInvestmentIncomeAndOtherIncome $ (8,861)rpm_NetInvestmentIncomeAndOtherIncome $ (5,899)rpm_NetInvestmentIncomeAndOtherIncome