Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME	$ 161,661	$ 110,430
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Currency translation adjustments	17,346	16,932
Employee benefit plans:
Actuarial loss (net of tax benefit of $1,342 and $261 for the three months ended March 31, 2018 and 2017, respectively)	(5,014)	(495)
Adjustment for items reclassified to earnings (net of tax expense of $216 and $276 for the three months ended March 31, 2018 and 2017, respectively)	1,062	1,086
OTHER COMPREHENSIVE INCOME, NET OF TAX	13,394	17,523
COMPREHENSIVE INCOME	175,055	127,953
LESS - COMPREHENSIVE INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS	1,969	2,877
COMPREHENSIVE INCOME ATTRIBUTABLE TO LAZARD LTD	$ 173,086	$ 125,076