Registration of securities issued in business combination transactions

Income Taxes -Open Tax Years by Major Tax Jurisdiction (Detail)

v2.4.0.8
Income Taxes -Open Tax Years by Major Tax Jurisdiction (Detail)
 12 Months Ended
Dec. 31, 2012
Colombia [Member]
  
Open Tax Years By Major Jurisdiction [Line Items]  
Open Tax Years by Major Tax Jurisdiction 2008-present
Kazakhstan [Member]
  
Open Tax Years By Major Jurisdiction [Line Items]  
Open Tax Years by Major Tax Jurisdiction 2007-present
Mexico [Member]
  
Open Tax Years By Major Jurisdiction [Line Items]  
Open Tax Years by Major Tax Jurisdiction 2007-present
Papua New Guinea [Member]
  
Open Tax Years By Major Jurisdiction [Line Items]  
Open Tax Years by Major Tax Jurisdiction 2010-present
Russia [Member]
  
Open Tax Years By Major Jurisdiction [Line Items]  
Open Tax Years by Major Tax Jurisdiction 2009-present
United States - Federal [Member]
  
Open Tax Years By Major Jurisdiction [Line Items]  
Open Tax Years by Major Tax Jurisdiction 2011-present