Stockholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended								12 Months Ended						1 Months Ended	12 Months Ended	1 Months Ended			0 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Lazard Ltd [Member]	Dec. 31, 2012 Lazard Ltd [Member]	Dec. 31, 2011 Lazard Ltd [Member]	Dec. 31, 2013 Class A Common Stock [Member]	Dec. 31, 2011 Class A Common Stock [Member]	Jan. 29, 2014 Class A Common Stock [Member] Subsequent Event [Member]	Dec. 31, 2013 Series A Preferred Stock [Member]	Dec. 31, 2012 Series A Preferred Stock [Member]	Dec. 31, 2013 December 2014 [Member]	Dec. 31, 2013 December 2015 [Member]
Schedule Of Stockholders Equity [Line Items]
Business acquisition number of common stock issued																	2,434,561
Conversion of stock, shares delivered from Class A common stock held by subsidiaries																	3,515,362
Shares in exchange of a like number of common membership interests													839,658	5,207,112	876,814
Common stock of parent held by subsidiary	8,317,065	8,317,065				12,802,938				8,317,065	12,802,938
Share repurchase remaining capacity	$ 121,589																				$ 21,589	$ 100,000
Authorized shares of preferred stock	15,000,000	15,000,000				15,000,000				15,000,000	15,000,000
Par value of preferred stock	$ 0.01	$ 0.01				$ 0.01				$ 0.01	$ 0.01
Convertible preferred stock																	14,100
Conversion of Series A preferred stock into Class A common stock (in shares)																	2,434,561
Outstanding shares of preferred stock																			7,921	7,921
DIVIDENDS DECLARED PER SHARE OF COMMON STOCK		$ 0.50	$ 0.25	$ 0.25		$ 0.60	$ 0.20	$ 0.20	$ 0.16	$ 1.000	$ 1.160	$ 0.605				$ 0.25		$ 0.30
Dividend payable date																Dec. 27, 2013		Feb. 21, 2014
Dividend date of record																Dec. 20, 2013		Feb. 10, 2014
Dividend declare date																Dec. 10, 2013		Jan. 29, 2014