Condensed Statements of Financial Condition (unaudited) (Parenthetical)	Mar. 31, 2013	Dec. 31, 2012
Partners' capital:
General partnership: units issued (in shares)	100,000	100,000
General Partner: units outstanding (in shares)	100,000	100,000
Limited partners: units issued (in shares)	105,465,870	105,073,342
Limited partners: units outstanding (in shares)	105,465,870	105,073,342