Related Parties Payable to Employees and Related Parties (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Related Party Transactions [Abstract]
Board of Director Fees	$ 266		$ 266
Amounts Due to UK Members	10,386		5,424
Amounts Due Pursuant to Tax Receivable Agreements	8,872	[1]	7,274	[1]
Payable to Employees and Related Parties	$ 19,524		$ 12,964

[1] Relates to the current portion of the Member exchange of LP Units for Class A Shares. The long-term portion of $175,771 and $165,350 is disclosed in Amounts Due Pursuant to Tax Receivable Agreements on the Consolidated Statements of Financial Condition at December 31, 2013 and 2012, respectively.