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, 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:
Net income	70,723			66,823			66,823	3,900
Other comprehensive income - 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					2,424,571
Delivery of Class A common stock in connection with share-based incentive compensation and related tax expense / benefit	$ (43,236)		(192,121)			$ 148,885	(43,236)
Delivery of Class A common stock in connection with share-based incentive compensation and related tax expense / 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
Balance at Dec. 31, 2016	1,293,813	$ 1,298	688,231	1,134,186	(314,222)	$ (273,506)	1,235,987	57,826
Balance (in shares) at Dec. 31, 2016		129,766,091				7,628,786
Adjustment for the cumulative effect on prior years from the adoption of new accounting guidance related to share-based incentive compensation at Dec. 31, 2016	81,544			81,544			81,544
Balance, as adjusted at Dec. 31, 2016	1,375,357	$ 1,298	688,231	1,215,730	(314,222)	$ (273,506)	1,317,531	57,826
Comprehensive income:
Net income	110,430			107,553			107,553	2,877
Other comprehensive income - net of tax	17,523				17,523		17,523
Amortization of share-based incentive compensation	77,527		77,527				77,527
Dividend-equivalents	(3,054)		25,977	(29,031)			(3,054)
Class A common stock dividends	(192,264)			(192,264)			(192,264)
Purchase of Class A common stock	$ (106,048)					$ (106,048)	(106,048)
Purchase of Class A common stock (in shares)	2,464,967					2,464,967
Delivery of Class A common stock in connection with share-based incentive compensation and related tax expense / benefit	$ (65,765)		(183,736)			$ 117,971	(65,765)
Delivery of Class A common stock in connection with share-based incentive compensation and related tax expense / benefit (in shares)						(3,214,282)
Business acquisitions and related equity transactions:
Class A common stock issuable (including related amortization)	74		74				74
Distributions to noncontrolling interests, net	(1,001)							(1,001)
Other	408							408
Balance at Mar. 31, 2017	$ 1,213,187	$ 1,298	$ 608,073	$ 1,101,988	$ (296,699)	$ (261,583)	$ 1,153,077	$ 60,110
Balance (in shares) at Mar. 31, 2017		129,766,091				6,879,471