Derivatives and Hedging Activity - Effect on Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivatives
Gain (loss) on derivative financial instruments, net	$ (37,586)	$ 20,253	$ (41,935)	$ (4,465)
Derivatives not designated as hedging instruments
Derivatives
Gain (loss) on derivative financial instruments, net	(37,586)	20,253	(41,935)	(4,465)
Interest rate swaps \| Derivatives not designated as hedging instruments
Derivatives
Gain (loss) on derivative financial instruments, net	(7,822)	(7,273)	(6,354)	(25,273)
Foreign exchange contracts \| Derivatives not designated as hedging instruments
Derivatives
Gain (loss) on derivative financial instruments, net	(29,422)	27,899	(35,164)	21,349
Credit index instruments \| Derivatives not designated as hedging instruments
Derivatives
Gain (loss) on derivative financial instruments, net	(342)	(373)	(417)	(541)
Cash flow hedges \| Interest rate swaps \| Derivatives designated as hedging instruments
Derivatives
Gain (Loss) Recognized in OCI (effective portion)	1	(136)	48	(504)
Gain (Loss) Reclassified from AOCI into Income (effective portion)	$ (1)	$ (88)	$ (30)	$ (183)

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

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+ References

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959

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