Income Taxes - Tax Years Subject to Examination by Major Jurisdiction Table (Detail)	12 Months Ended
	Dec. 31, 2013
United States [Member] | Minimum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2007
United States [Member] | Maximum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2013
China [Member] | Minimum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2009
China [Member] | Maximum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2013
Algeria [Member] | Minimum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2010
Algeria [Member] | Maximum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2013
Ghana [Member] | Minimum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2006
Ghana [Member] | Maximum [Member]
Income TaxExamination [Line Items]
Tax year subject to examination	2013