Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In-Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Class A Common Stock Held By Subsidiaries [Member]	Total Lazard Ltd Stockholders' Equity [Member]	Noncontrolling Interests [Member]	Series A Preferred Stock [Member]
Balance at Dec. 31, 2014	$ 770,057	$ 1,298	$ 702,800	$ 464,655	$ (200,766)	$ (261,243)	$ 706,744	$ 63,313
Balance (in shares) at Dec. 31, 2014		129,766,091				7,450,745			7,921
Comprehensive income (loss):
NET INCOME	62,646			55,953			55,953	6,693
Other comprehensive income (loss) - net of tax	(32,728)				(32,728)		(32,728)
Amortization of share-based incentive compensation	77,923		77,923				77,923
Dividend-equivalents	(1,155)		22,898	(24,053)			(1,155)
Class A common stock dividends	(158,390)			(158,390)			(158,390)
Purchase of Class A common stock	(82,963)					$ (82,963)	(82,963)
Purchase of Class A common stock (in shares)						1,677,464
Delivery of Class A common stock in connection with share-based incentive compensation and related tax benefit	(92,390)		(294,327)			$ 201,937	(92,390)
Delivery of Class A common stock in connection with shared-based incentive compensation and related tax benefit (in shares)						(5,370,128)
Business acquisitions and related equity transactions:
Class A common stock issuable (including related amortization)	89		89				89
Distributions to noncontrolling interests, net	(5,784)							(5,784)
Balance at Mar. 31, 2015	537,305	$ 1,298	509,383	338,165	(233,494)	$ (142,269)	473,083	64,222
Balance (in shares) at Mar. 31, 2015		129,766,091				3,758,081			7,921
Balance at Dec. 31, 2015	1,367,306	$ 1,298	600,034	1,123,728	(234,356)	$ (177,249)	1,313,455	53,851
Balance (in shares) at Dec. 31, 2015		129,766,091				4,253,381			7,921
Comprehensive income (loss):
NET INCOME	70,723			66,823			66,823	3,900
Other comprehensive income (loss) - net of tax	12,784				12,784		12,784
Amortization of share-based incentive compensation	94,638		94,638				94,638
Dividend-equivalents	(1,568)		23,793	(25,361)			(1,568)
Class A common stock dividends	(194,382)			(194,382)			(194,382)
Purchase of Class A common stock	(83,140)					$ (83,140)	(83,140)
Purchase of Class A common stock (in shares)						2,424,571
Delivery of Class A common stock in connection with share-based incentive compensation and related tax benefit	(43,236)		(192,121)			$ 148,885	(43,236)
Delivery of Class A common stock in connection with shared-based incentive compensation and related tax benefit (in shares)						(3,674,957)
Business acquisitions and related equity transactions:
Distributions to noncontrolling interests, net	(331)							(331)
Other	(46)		(46)				(46)
Balance at Mar. 31, 2016	$ 1,222,748	$ 1,298	$ 526,298	$ 970,808	$ (221,572)	$ (111,504)	$ 1,165,328	$ 57,420
Balance (in shares) at Mar. 31, 2016		129,766,091				3,002,995			7,921