Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

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- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ 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 (e)

-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

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Derivative Financial Instruments - Gain (Loss) Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	$ 35,496	$ 29,702	$ 49,345	$ (8,482)
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Foreign Currency Futures Contracts [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	(202)	2,952	806	5,794
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Foreign Currency Forward Contracts [Member] \| Investment Income (Loss) and Other, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	284	(120)	(10)	312
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Equity Futures Contracts [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	11,361	6,044	13,738	14,781
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Equity Swap Contracts [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	739	1,061	1,068	2,343
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Listed Options [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	(2,631)	2,212	(16,181)	(71,664)
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Fixed Income Futures Contracts [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	16,377	5,118	24,921	13,947
Derivative Instruments Not Designated as Hedging Instruments [Member] \| Commodity Futures Contracts [Member] \| Trading Revenues, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, Gain (Loss)	9,568	12,435	25,003	26,005
Derivative Instruments Designated as Hedging Instruments [Member] \| Foreign Currency Forward Contracts [Member] \| Accumulated Other Comprehensive Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments designated as hedging instruments	$ (6)	$ 0	$ (6)	$ 168