Note 13 - Acquisition of Aurizon Mines Ltd. (Detail) In Millions, except Share data, unless otherwise specified	0 Months Ended		1 Months Ended
	May 07, 2013 USD ($)	May 07, 2013 CAD	Mar. 31, 2013 CAD	Mar. 31, 2013 In The Money Stock Options [Member]
Business Acquisition, Share Price (in Dollars per share)			4.75
Business Acquisition Per Share Issued			0.9953
Business Acquisition, Cost of Acquired Entity, Cash Paid (in Dollars)			513.6
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares			57,000,000	747,132
Potentail Business Acquisition Per Share Price (in Dollars per share)			3.11
Potentail Business Acquitision Shares Issued			0.34462
Business Acquisition Shares Outstanding of Entity Acquired			164,838,377
Business Acquisition Shares Issued And Outstanding of Acquired Entity			165,585,509
Share Price (in Dollars per share)			3.29
Exchange Rate			0.9923%
Business Acquisition, Cost of Acquired Entity, Purchase Price (in Dollars and Dollars)	695.5	700.9	513.6
Business Acquisition Cost Sensitivity To Change In Share Price (in Dollars and Dollars)	$ 18.6	18.7