Consolidated Statements of Changes in Partners' Capital (Net Asset Value) (Class A, Class B and Legacy Class) (USD $)	Total	Class A	Class A General Partner	Class A Limited Partners	Class B	Class B General Partner	Class B Limited Partners	Legacy 1 Class	Legacy 1 Class General Partner	Legacy 1 Class Limited Partners	Legacy 2 Class	Legacy 2 Class General Partner	Legacy 2 Class Limited Partners
Partners' capital, (net asset value) at Dec. 31, 2011				$ 41,622,105			$ 460,685,410			$ 4,753,458			$ 14,932,071
Partners' capital, (net asset value) at Dec. 31, 2011	798,842,191
Partners' capital, (net asset value) at Dec. 31, 2011			3,898,734			469,305			935,031			903,063
Partners' capital, (net asset value) (in units) at Dec. 31, 2011				32,119.81			419,169.11			5,210.84			16,534.92
Partners' capital, (net asset value) (in units) at Dec. 31, 2011			3,008.66			427.01			1,025.00			1,000.00
Net asset value per unit at beginning of period (in dollars per unit) at Dec. 31, 2011		$ 1,295.84	$ 1,295.84	$ 1,295.84	$ 1,099.04	$ 1,099.04	$ 1,099.04	$ 912.23	$ 912.23	$ 912.23	$ 903.06	$ 903.06	$ 903.06
Increase (Decrease) in Partners' Capital
Contributions	21,950,721									46,650			583,158
Contributions (in units)										51.19			643.95
Redemptions	(97,210,099)		(650,000)	(5,210,041)		(461,824)	(63,723,791)			(379,681)			(2,098,719)
Redemptions (in units)			(508.88)	(3,995.96)		(427.01)	(57,925.41)			(412.65)			(2,318.46)
Net income (loss)	(2,392,867)		(23,675)	(128,394)		(7,481)	(2,959,538)		6,481	33,964		4,524	70,612
Partners' capital, (net asset value) at Jun. 30, 2012				36,283,670			394,002,081			4,454,391			13,487,122
Partners' capital, (net asset value) at Jun. 30, 2012	721,189,946
Partners' capital, (net asset value) at Jun. 30, 2012			3,225,059						941,512			907,587
Partners' capital, (net asset value) (in units) at Jun. 30, 2012				28,123.85			361,243.70			4,849.38			14,860.41
Partners' capital, (net asset value) (in units) at Jun. 30, 2012			2,499.78						1,025.00			1,000.00
Net asset value per unit at end of period (in dollars per unit) at Jun. 30, 2012		$ 1,290.14	$ 1,290.14	$ 1,290.14	$ 1,090.68	$ 1,090.68	$ 1,090.68	$ 918.55	$ 918.55	$ 918.55	$ 907.59	$ 907.59	$ 907.59
Partners' capital, (net asset value) at Dec. 31, 2012		31,269,640		31,269,640	330,303,791		330,303,791	3,851,016		3,851,016	11,061,307		11,061,307
Partners' capital, (net asset value) at Dec. 31, 2012	636,740,050
Partners' capital, (net asset value) at Dec. 31, 2012		3,040,653	3,040,653					897,998	897,998		864,602	864,602
Partners' capital, (net asset value) (in units) at Dec. 31, 2012		25,707.33		25,707.33	322,257.31		322,257.31	4,395.66		4,395.66	12,793.52		12,793.52
Partners' capital, (net asset value) (in units) at Dec. 31, 2012		2,499.78	2,499.78					1,025.00	1,025.00		1,000.00	1,000.00
Net asset value per unit at beginning of period (in dollars per unit) at Dec. 31, 2012		$ 1,216.37	$ 1,216.37	$ 1,216.37	$ 1,024.97	$ 1,024.97	$ 1,024.97	$ 876.10	$ 876.10	$ 876.10	$ 864.60	$ 864.60	$ 864.60
Increase (Decrease) in Partners' Capital
Contributions	18,974,662												426,064
Contributions (in units)													493.95
Redemptions	(82,191,402)		(1,000,000)	(4,857,922)			(41,174,199)			(469,317)			(2,636,258)
Redemptions (in units)			(839.54)	(4,039.33)			(40,666.29)			(532.94)			(3,072.07)
Net income (loss)	(29,673,926)		(124,753)	(1,407,097)			(16,178,438)		(36,357)	(134,604)		(35,952)	(386,119)
Partners' capital, (net asset value) at Jun. 30, 2013		25,004,621		25,004,621	272,951,154		272,951,154	3,247,095		3,247,095	8,464,994		8,464,994
Partners' capital, (net asset value) at Jun. 30, 2013	543,849,384
Partners' capital, (net asset value) at Jun. 30, 2013		$ 1,915,900	$ 1,915,900					$ 861,641	$ 861,641		$ 828,650	$ 828,650
Partners' capital, (net asset value) (in units) at Jun. 30, 2013		21,668.00		21,668.00	281,591.02		281,591.02	3,862.72		3,862.72	10,215.40		10,215.40
Partners' capital, (net asset value) (in units) at Jun. 30, 2013		1,660.24	1,660.24					1,025.00	1,025.00		1,000.00	1,000.00
Net asset value per unit at end of period (in dollars per unit) at Jun. 30, 2013		$ 1,153.99	$ 1,153.99	$ 1,153.99	$ 969.32	$ 969.32	$ 969.32	$ 840.63	$ 840.63	$ 840.63	$ 828.65	$ 828.65	$ 828.65