Summary of Impact of Derivative Financial Instruments to Condensed Consolidated Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	$ 12,385us-gaap_GainLossOnSaleOfDerivatives	$ 892us-gaap_GainLossOnSaleOfDerivatives
Net Change in Unrealized Gain (Loss)	(26,942)us-gaap_UnrealizedGainLossOnDerivatives	(8,846)us-gaap_UnrealizedGainLossOnDerivatives
Net Investment Hedges \| Foreign Currency Contracts
Derivative Financial Instruments [Line Items]
Hedge Ineffectiveness	240
Freestanding Derivatives \| Foreign Currency Contracts
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	14,073	1,439
Net Change in Unrealized Gain (Loss)	(23,025)	(8,117)
Freestanding Derivatives \| Interest Rate Contracts
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	(3,514)	(833)
Net Change in Unrealized Gain (Loss)	(995)	(2,542)
Freestanding Derivatives \| Credit Default Swaps
Derivative Financial Instruments [Line Items]
Realized Gains (Losses)	1,826	286
Net Change in Unrealized Gain (Loss)	$ (2,922)	$ 1,813

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Amount of gain (loss) from the ineffectiveness of the hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 50

-Paragraph 1

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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- Definition

The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13(h))

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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

+ References

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