Gain On Sale Of Assets (Details) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended			2 Months Ended	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Feb. 29, 2012 Burkina Faso Exploration Properties [Member]	Dec. 31, 2012 Burkina Faso Exploration Properties [Member]	Dec. 31, 2011 Burkina Faso Exploration Properties [Member]	Dec. 31, 2010 Burkina Faso Exploration Properties [Member]	Dec. 31, 2012 Saramacca [Member]	Dec. 31, 2012 Saramacca [Member]	Dec. 31, 2011 Saramacca [Member]	Dec. 31, 2010 Saramacca [Member]	Mar. 01, 2013 Subsequent Event [Member] Saramacca [Member]	Mar. 01, 2013 Subsequent Event [Member] Saramacca [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash receipts on sale of assets				$ 6,600,000				$ 8,000,000				$ 1,000,000	$ 9,000,000
Shares received for sale of asset, shares	1,155,200	0		21,700,000		4,000,000
Shares received for sale of asset, value	(805,000)	0		15,800,000
Gain on sale of assets	$ 31,577,000	$ 1,350,000	$ 1,171,000		$ 22,400,000	$ 0	$ 0		$ 9,200,000	$ 0	$ 0