XML 52 R97.htm IDEA: XBRL DOCUMENT v2.4.1.9
Incentive Plans - Schedule of Issuance of RSUs and Charges to Retained Earnings (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Number of RSUs issued 375,954laz_IssuanceOfRestrictedStockUnitsInConnectionWithDividendParticipationRights 454,059laz_IssuanceOfRestrictedStockUnitsInConnectionWithDividendParticipationRights 920,791laz_IssuanceOfRestrictedStockUnitsInConnectionWithDividendParticipationRights
Charges to retained earnings, net of estimated forfeitures $ 17,536laz_ChargeToRetainedEarningsPertainingToIssuanceOfRestrictedStockUnitsInConnectionWithParticipationRights $ 16,927laz_ChargeToRetainedEarningsPertainingToIssuanceOfRestrictedStockUnitsInConnectionWithParticipationRights $ 24,990laz_ChargeToRetainedEarningsPertainingToIssuanceOfRestrictedStockUnitsInConnectionWithParticipationRights