XML 123 R109.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Stock Incentive Plan (Schedule of Share-based Compensation, Unearned Compensation Related to RSU's) (Details) - Restricted Stock Units (RSUs) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Changes In Unearned Compensation [Roll Forward] |  |  |
Unearned compensation at beginning of year | $ 142,060 | $ 135,535 | $ 132,310
RSUs granted, net of cancellations | 62,418 | 60,628 | 56,711
RSUs expensed | 49,200 | (47,611) | (46,441)
RSUs forfeitures | 7,198 | (6,492) | (7,045)
Unearned compensation at end of year | $ 148,080 | $ 142,060 | $ 135,535

X
- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Changes In Unearned Compensation [Roll Forward] + References No definition available. + Details
Name: | wrb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsChangesInUnearnedCompensationRollForward
Namespace Prefix: | wrb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options, Unearned Compensation Expense + References No definition available. + Details
Name: | wrb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnearnedCompensationExpense
Namespace Prefix: | wrb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options, Unearned Compensation, Expenses In Period + References No definition available. + Details
Name: | wrb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnearnedCompensationExpensesInPeriod
Namespace Prefix: | wrb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options, Unearned Compensation, Forfeiture Adjustments In Period + References No definition available. + Details
Name: | wrb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnearnedCompensationForfeitureAdjustmentsInPeriod
Namespace Prefix: | wrb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options, Unearned Compensation, Grants in Period Net Of Cancellations + References No definition available. + Details
Name: | wrb_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnearnedCompensationGrantsinPeriodNetOfCancellations
Namespace Prefix: | wrb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |