Derivatives and Hedging Instruments - Summary of Fair Value of Derivative Instruments as Recorded in Company's Condensed Consolidated Statements of Financial Condition (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Other Liabilities [Member] | Interest rate swaps [Member]
Derivative [Line Items]
Derivatives designated as hedging instruments	$ (139)	$ (645)
Other Liabilities [Member] | Foreign currency exchange contracts [Member]
Derivative [Line Items]
Derivatives designated as hedging instruments	(5,567)	(2,010)
Other assets [Member] | Interest rate cap [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	$ 206