Property, Plant And Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment at Cost	$ 507,442	$ 473,832
Accumulated Depreciation	(246,456)	(221,701)
Property, Plant and Equipment Net Book Value	260,986	252,131
Wassa/HBB
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment at Cost	120,766	106,631
Accumulated Depreciation	(65,463)	(52,430)
Property, Plant and Equipment Net Book Value	55,303	54,201
Corporate & other
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment at Cost	1,363	1,378
Accumulated Depreciation	(925)	(879)
Property, Plant and Equipment Net Book Value	438	499
Bogoso/Prestea | Bogoso/Prestea
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment at Cost	189,247	179,216
Accumulated Depreciation	(112,838)	(109,519)
Property, Plant and Equipment Net Book Value	76,409	69,697
Bogoso Refactory Plant | Bogoso/Prestea
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment at Cost	196,066	186,607
Accumulated Depreciation	(67,230)	(58,873)
Property, Plant and Equipment Net Book Value	$ 128,836	$ 127,734