Income Taxes (TaxReturns) (Details) NOK in Millions, BRL in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016 NOK jurisdiction	Dec. 31, 2016 USD ($)	May 19, 2014 BRL	May 19, 2014 USD ($)	Dec. 31, 2005 BRL	Dec. 31, 2005 USD ($)
Income Tax Examination
Number of jurisdictions with extensions beyond statute of limitations	2
Maximum number of years agreed to extensions beyond the statute of limitations	20 years
Brazil tax assessment for income tax returns					BRL 818	$ 251
Minimum
Income Tax Examination
Range of tax returns are subject to examination	3 years
Maximum
Income Tax Examination
Range of tax returns are subject to examination	6 years
Norway Tax Assessments Prior to 2012
Income Tax Examination
Norway tax assessment due to 2001 dividend payment, including interest	NOK 412	$ 48
Brazil Tax Assessments 2009 And 2010
Income Tax Examination
Brazil tax assessment for income tax returns			BRL 139	$ 43