Asset Retirement Obligations and Restricted Deposits (Detail) (USD $)			12 Months Ended
	Jan. 31, 2011 Tournigan Energy [Member] WDEQ [Member]	Jan. 31, 2010 Tournigan Energy [Member] WDEQ [Member]	Jan. 31, 2011 WDEQ [Member]	Jan. 31, 2010 WDEQ [Member]	Oct. 31, 2012 Arizona BLM [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