Summary of Impact of Derivative Financial Instruments to Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	$ (2,563)	$ (3,994)	$ 7,591	$ (3,102)
Net Change in Unrealized Gain (Loss)	5,017	(12,573)	(9,675)	(21,419)
Net Investment Hedges | Foreign Currency Contracts
Derivative Financial Instruments [Line Items]
Hedge Ineffectiveness	(11)		229
Freestanding Derivatives | Foreign Currency Contracts
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	(3,160)	(4,420)	8,903	(2,981)
Net Change in Unrealized Gain (Loss)	2,779	(13,827)	(8,245)	(21,944)
Freestanding Derivatives | Interest Rate Contracts
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	(1,358)	(570)	(5,093)	(1,403)
Net Change in Unrealized Gain (Loss)	4,707	(1,731)	3,961	(4,273)
Freestanding Derivatives | Credit Default Swaps
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	1,955	996	3,781	1,282
Net Change in Unrealized Gain (Loss)	$ (2,469)	$ 2,985	$ (5,391)	$ 4,798