NET INCOME PER UNIT (Details) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012	Jul. 31, 2011	Jan. 31, 2012
NET INCOME PER UNIT
Accrued income receivable	$ 5,116,862		$ 5,116,862		$ 387,980
Number of units outstanding (in units)	13,120,010	13,120,010	13,120,010	13,120,010