Exploration Costs (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		211 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012
Exploration cost related to mining operations
Total Exploration costs	$ 1,179	$ 2,925	$ 2,330	$ 5,615	$ 91,383
Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs	457	561	824	1,065	7,296
Cameroon Africa [Member]
Exploration cost related to mining operations
Total Exploration costs	722	2,364	1,506	4,550	84,087
Cameroon Africa [Member] | Property evaluation [Member]
Exploration cost related to mining operations
Total Exploration costs	196	1,075	575	2,480	53,451
Cameroon Africa [Member] | Office costs [Member]
Exploration cost related to mining operations
Total Exploration costs	526	1,289	931	2,070	30,636
Colorado/Wyoming [Member] | Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs		20	2	57	2,068
Arizona [Member] | Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs	119	169	210	255	1,505
New Mexico [Member] | Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs	33	69	105	207	666
New Caledonia [Member] | Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs	244	208	423	368	2,284
Papua New Guinea [Member] | Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs	40	87	63	169	329
Other [Member] | Other Projects [Member]
Exploration cost related to mining operations
Total Exploration costs	$ 21	$ 8	$ 21	$ 9	$ 444