Income Taxes (Details 6)	12 Months Ended
	Dec. 31, 2011
United States [Member]
Key jurisdictions of Company's earliest open tax years
Open Tax Years by Major Tax Jurisdiction	2004
Canada [Member]
Key jurisdictions of Company's earliest open tax years
Open Tax Years by Major Tax Jurisdiction	2007
Egypt [Member]
Key jurisdictions of Company's earliest open tax years
Open Tax Years by Major Tax Jurisdiction	1998
Australia [Member]
Key jurisdictions of Company's earliest open tax years
Open Tax Years by Major Tax Jurisdiction	2007
United Kingdom [Member]
Key jurisdictions of Company's earliest open tax years
Open Tax Years by Major Tax Jurisdiction	2010
Argentina [Member]
Key jurisdictions of Company's earliest open tax years
Open Tax Years by Major Tax Jurisdiction	2004