Income Taxes - Provision (Benefit) for Income Taxes from Continuing Operations (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Denmark [Member]
Income Tax Expense Benefit Continuing Operations [Line Items]
Effect of hydrocarbon income tax law change	$ 674
Norway [Member]
Income Tax Expense Benefit Continuing Operations [Line Items]
Effect of change in hydrocarbon and base corporate income tax rates	$ 8