Stockholders' Equity (Schedule Of Group Distributions) (Details) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Amounts distributed by Lazard Group	$ 54,689	$ 45,167
LAZ-MD Holdings [Member]
Amounts distributed by Lazard Group	3,280	8,453
Subsidiaries Of Lazard Ltd [Member]
Amounts distributed by Lazard Group	$ 51,409	$ 36,714