Condensed Statements Of Income (Parenthetical)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed Statements Of Income
Interests outstanding	46,280.3	46,280.3	46,280.3	46,280.3