Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME	$ 393,692	$ 992,932	$ 434,063
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Currency translation adjustments	(57,920)	(51,182)	(49,971)
Employee benefit plans:
Actuarial gain (loss) (net of tax expense (benefit) of $(5,205), $5,644 and $(9,045) for the years ended December 31, 2016, 2015 and 2014, respectively)	(24,473)	11,283	(21,983)
Adjustment for items reclassified to earnings (net of tax expense of $1,757, $1,507 and $1,923 for the years ended December 31, 2016, 2015, and 2014, respectively)	2,526	6,309	4,749
OTHER COMPREHENSIVE LOSS, NET OF TAX	(79,867)	(33,590)	(67,205)
COMPREHENSIVE INCOME	313,825	959,342	366,858
LESS - COMPREHENSIVE INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS	5,993	6,559	6,785
COMPREHENSIVE INCOME ATTRIBUTABLE TO LAZARD LTD	$ 307,832	$ 952,783	$ 360,073