Derivatives and Hedging Instruments - Summary of Fair Value of Derivative Instruments as Recorded in Company's Consolidated Statements of Financial Condition (Detail) (Fair Value, Measurements, Recurring [Member], Foreign Currency Exchange Contracts [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Other Liabilities [Member]
Derivative [Line Items]
Foreign currency exchange contracts, liabilities	$ (474)	$ (1,037)
Other Assets [Member]
Derivative [Line Items]
Foreign currency exchange contracts, assets	1,064	768
Fair Value, Inputs, Level 2 [Member] | Other Liabilities [Member]
Derivative [Line Items]
Foreign currency exchange contracts, liabilities	(474)	(1,037)
Fair Value, Inputs, Level 2 [Member] | Other Assets [Member]
Derivative [Line Items]
Foreign currency exchange contracts, assets	$ 1,064	$ 768