Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME	$ 76,515	$ 48,196	$ 207,922	$ 218,185
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Currency translation adjustments	34,326	(26,760)	5,964	(30,033)
Employee benefit plans:
Prior service cost (credit) (net of tax (benefit) expense of $(22) for the three months ended September 30, 2020 and $16 for the nine months ended September 30, 2020)	(110)		74
Actuarial gain (loss) (net of tax (benefit) expense of $(1,644) and $(1,607) for the three months ended September 30, 2020 and 2019, respectively, and $(25) and $1,113 for the nine months ended September 30, 2020 and 2019, respectively)	(6,424)	9,050	2,971	11,911
Adjustment for items reclassified to earnings (net of tax expense of $412 and $172 for the three months ended September 30, 2020 and 2019, respectively, and $1,088 and $524 for the nine months ended September 30, 2020 and 2019, respectively)	1,345	1,074	4,855	3,319
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	29,137	(16,636)	13,864	(14,803)
COMPREHENSIVE INCOME	105,652	31,560	221,786	203,382
LESS - COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO NONCONTROLLING INTERESTS	1,424	1,493	(4,649)	8,662
COMPREHENSIVE INCOME ATTRIBUTABLE TO LAZARD LTD	$ 104,228	$ 30,067	$ 226,435	$ 194,720