Related Parties - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended					3 Months Ended	12 Months Ended			1 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Administrative Services Agreement [Member]	Dec. 31, 2013 Employee Benefits Agreement [Member]	Dec. 31, 2013 Master Separation Agreement [Member]	Dec. 31, 2013 Business Alliance Agreement [Member]	Dec. 31, 2011 LAI Holdings [Member]	Dec. 31, 2013 MBA Lazard Holdings S.A. [Member]	Dec. 31, 2012 MBA Lazard Holdings S.A. [Member]	Dec. 31, 2011 MBA Lazard Holdings S.A. [Member]	Feb. 28, 2009 North American Fund Management Activities [Member]	May 31, 2005 North American Fund Management Activities [Member]	Dec. 15, 2009 European Fund Management Activities [Member]	May 31, 2005 European Fund Management Activities [Member]	Dec. 31, 2013 LAZ-MD Holdings [Member] Administrative Services Agreement [Member]	Dec. 31, 2012 LAZ-MD Holdings [Member] Administrative Services Agreement [Member]	Dec. 31, 2011 LAZ-MD Holdings [Member] Administrative Services Agreement [Member]	Dec. 31, 2013 LFCM Holdings [Member]	Dec. 31, 2012 LFCM Holdings [Member]	Dec. 31, 2011 LFCM Holdings [Member]	Dec. 31, 2013 LFCM Holdings [Member] Administrative and Support Services and Others [Member]	Dec. 31, 2012 LFCM Holdings [Member] Administrative and Support Services and Others [Member]	Dec. 31, 2013 LFCM Holdings [Member] Referral Fees for Underwriting and Private Placement Transactions [Member]	Dec. 31, 2012 LFCM Holdings [Member] Referral Fees for Underwriting and Private Placement Transactions [Member]	Dec. 31, 2013 LFCM Holdings [Member] Referral Fees [Member]	Dec. 31, 2012 LFCM Holdings [Member] Referral Fees [Member]
Related Party Transaction [Line Items]
Transaction agreement date		May 10, 2005	May 10, 2005	May 10, 2005	May 10, 2005
Days notice of termination	180 days
Amounts recorded relating to the administrative services agreement														$ 1,000	$ 1,000	$ 750	$ 1,456	$ 7,637	$ 10,277
Amounts recorded relating to net referral fees for underwriting, private placement, and restructuring transactions																	(1,646)	5,947	18,862
Receivables from related party																				3,112	14,299	4,682	6,230
Payables to related party																								3,051	2,943
Payable pursuant to the tax receivable agreement																	1,249
Percentage of ownership							50.00%	50.00%	50.00%
Referral fees for restructuring transactions							(2,221)	1,506	1,866
Administrative services agreement date														Dec. 31, 2014
Business Acquisition - option cost to acquire entity, purchase price											8,000		2,000
Business acquisition, cost of acquired entity, exercised price												2,000
Prepaid option excise price										5,500
Exercisable price for North American activities										2,500
Date the remaining option to purchase North American fund management is exercisable										May 10, 2014
Write-off of acquired option capitalized cost						$ 5,500