Derivative Instruments and Hedging Activities (Tables)

12 Months Ended

Dec. 31, 2016

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

Derivatives not designated as hedging instruments:

As of December 31, 2015
	Asset		Liability
Type of	Derivatives		Derivatives			Net
Futures Contracts	Fair Value		Fair Value			Fair Value
Agriculture	$	32,649	$	(61,049	)	$	(28,400	)
Currency		26,412		(863	)		25,549
Energy		104,889		(74,035	)		30,854
Indices		5,225		(23,774	)		(18,549	)
Interest rates		4,782		(21,653	)		(16,871	)
Metals		11,985		(9,213	)		2,772
	$	185,942	$	(190,587	)	$	(4,645	)

Schedule of Derivative Instruments Included in Trading Activities [Table Text Block]

Trading gain (loss) for the following periods:

	Year ended December 31,
Type of Futures Contracts	2016			2015			2014
Agriculture	$	140,538		$	(177,298	)	$	(42,004	)
Currency		(117,250	)		(480,313	)		790,640
Energy		(165,154	)		687,431			126,535
Indices		(59,458	)		(226,266	)		(566,210	)
Interest rates		297,195			16,128			188,370
Metals		(133,786	)		15,436			21,168
	$	(37,915	)	$	(164,882	)	$	518,499