Derivative Instruments (Details 3) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	$ 10,980,359	$ 6,152,000
Agricultural contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	(2,751,148)	(3,640,157)
Currencies contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	5,269,387	(15,310,478)
Energy contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	(3,339,691)	16,483,097
Interest rates contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	(5,876,256)	(15,994,930)
Meats contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	29,509	104,952
Metals contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	(1,319,442)	(5,715,264)
Soft commodities contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	2,340,443	(798,746)
Stock indices contracts and equity options contracts
Net gain (loss) from futures and forward trading
Total realized and changed in unrealized net gain (loss) from futures and forward trading	16,627,557	31,023,526
Futures and Forward Trading
Net gain (loss) from futures and forward trading
Realized	8,506,968	13,792,108
Change in unrealized	2,473,391	(7,640,108)
Total realized and changed in unrealized net gain (loss) from futures and forward trading	$ 10,980,359	$ 6,152,000