XML 35 R23.htm IDEA: XBRL DOCUMENT v2.4.1.9
INVESTMENTS Debt and Common Stock Securities (Details) (USD $)
 3 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Fixed income securities in unrealized loss positions    
Other Investments $ 11,402,000us-gaap_OtherInvestments $ 11,597,000us-gaap_OtherInvestments
Total tax benefit on investments in housing tax credit partnership 300,000rli_TaxExpenseBenefitOnInvestments  
Investment in FHLBC 1,800,000us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure 1,800,000us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization Member    
Fixed income securities in unrealized loss positions    
Other Investments $ 9,600,000us-gaap_OtherInvestments
/ us-gaap_InvestmentTypeAxis
= rli_InvestmentInLowIncomeHousingTaxCreditPartnershipNetOfAmortizationMember		 $ 9,800,000us-gaap_OtherInvestments
/ us-gaap_InvestmentTypeAxis
= rli_InvestmentInLowIncomeHousingTaxCreditPartnershipNetOfAmortizationMember