Asset Retirement Obligation and Restricted Deposits (Detail) (USD $)		12 Months Ended
	Jan. 31, 2011 WDEQ [Member] Tournigan Energy [Member]	Jan. 31, 2011 WDEQ [Member]	Jan. 31, 2010 WDEQ [Member]	Jan. 31, 2013 Arizona BLM [Member]	Jan. 31, 2010 Tournigan Energy [Member]
Restricted Cash and Investments, Noncurrent		$ 304,400	$ 575,600	$ 35,000
Mineral Extraction Processing and Marketing Costs		127,000	340,000
Business Acquisition, Cost of Acquired Entity, Transaction Costs	130,000				200,000
Other General Expense		$ 47,000