XML 94 R90.htm IDEA: XBRL DOCUMENT v2.4.1.9
Indebtedness (Details) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Subsidiary Debt    
Debt Instrument [Line Items]    
Face Value $ 153,549,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember		  
Carrying Value 154,223,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember		 [1] 77,173,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember		 [1]
Repayments in 2014   76,000,000us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember
Repayments in 2015   33,000,000us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember
Repayments in 2016   42,000,000us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember
Repayments thereafter   3,000,000wrb_LongtermDebtMaturitiesRepaymentsofPrincipalafterYearThree
/ us-gaap_DebtInstrumentAxis
= wrb_SubsidiaryDebtMember
Senior Notes and Other Debt    
Debt Instrument [Line Items]    
Face Value 2,130,052,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LongtermDebtTypeAxis
= wrb_SeniorNotesandOtherDebtMember		  
Carrying Value 2,115,527,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= wrb_SeniorNotesandOtherDebtMember		 1,692,442,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= wrb_SeniorNotesandOtherDebtMember
Senior Notes | Senior Notes due May 15, 2015    
Debt Instrument [Line Items]    
Rate   5.60%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMay152015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 200,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMay152015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 199,930,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMay152015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 199,744,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMay152015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due August 15, 2019    
Debt Instrument [Line Items]    
Rate   6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueAugust152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 150,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueAugust152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 149,342,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueAugust152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 149,199,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueAugust152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due September 15, 2019    
Debt Instrument [Line Items]    
Rate   7.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 300,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 298,800,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 298,546,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember152019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due September 15, 2020    
Debt Instrument [Line Items]    
Rate   5.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember132020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 300,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember132020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 298,074,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember132020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 297,738,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueSeptember132020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due January 1, 2022    
Debt Instrument [Line Items]    
Rate   8.70%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueJanuary12022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 76,503,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueJanuary12022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 76,048,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueJanuary12022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 76,004,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueJanuary12022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due March 15, 2022    
Debt Instrument [Line Items]    
Rate   4.625%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMaarch152022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 350,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMaarch152022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 346,999,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMaarch152022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 346,581,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueMaarch152022Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due February 15, 2037    
Debt Instrument [Line Items]    
Rate   6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueFebruary152037Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 250,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueFebruary152037Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 247,566,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueFebruary152037Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 247,457,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesDueFebruary152037Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Senior Notes due August 1, 2044 [Member]    
Debt Instrument [Line Items]    
Rate   4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesdueAugust12044Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Face Value 350,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesdueAugust12044Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		  
Carrying Value 344,545,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesdueAugust12044Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember		 0us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= wrb_SeniorNotesdueAugust12044Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Junior Subordinated Debt [Member]    
Debt Instrument [Line Items]    
Face Value   350,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_JuniorSubordinatedDebtMember
Carrying Value $ 340,060,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_JuniorSubordinatedDebtMember		 $ 339,800,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_JuniorSubordinatedDebtMember
Junior Subordinated Debt [Member] | Five Point Six Two Five Percent Subordinated Debentures [Member]    
Debt Instrument [Line Items]    
Rate   5.625%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= wrb_FivePointSixTwoFivePercentSubordinatedDebenturesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_JuniorSubordinatedDebtMember
[1] Subsidiary debt is due as follows: $76 million in 2015, $33 million in 2016, $42 million in 2017 and $3 million thereafter.