Income Taxes - Key Jurisdictions of Company's Earliest Open Tax Years (Detail)	12 Months Ended
	Dec. 31, 2012
United States [Member]
Open Tax Years By Major Jurisdiction [Line Items]
Open Tax Years by Major Tax Jurisdiction	2004
Canada [Member]
Open Tax Years By Major Jurisdiction [Line Items]
Open Tax Years by Major Tax Jurisdiction	2008
Egypt [Member]
Open Tax Years By Major Jurisdiction [Line Items]
Open Tax Years by Major Tax Jurisdiction	1998
Australia [Member]
Open Tax Years By Major Jurisdiction [Line Items]
Open Tax Years by Major Tax Jurisdiction	2008
United Kingdom [Member]
Open Tax Years By Major Jurisdiction [Line Items]
Open Tax Years by Major Tax Jurisdiction	2011
Argentina [Member]
Open Tax Years By Major Jurisdiction [Line Items]
Open Tax Years by Major Tax Jurisdiction	2005