Supplemental disclosures with respect to cash flows (Narrative) (Details) (USD $)	9 Months Ended
	Oct. 31, 2012
Supplemental Disclosures With Respect To Cash Flows 1	20,555,571
Supplemental Disclosures With Respect To Cash Flows 2	2,037,113
Supplemental Disclosures With Respect To Cash Flows 3	$ 0
Supplemental Disclosures With Respect To Cash Flows 4	38,998
Supplemental Disclosures With Respect To Cash Flows 5	22,687,507
Supplemental Disclosures With Respect To Cash Flows 6	1,165,462
Supplemental Disclosures With Respect To Cash Flows 7	0
Supplemental Disclosures With Respect To Cash Flows 8	$ 561,816