Subsequent Events (Details) In Millions, unless otherwise specified	1 Months Ended			0 Months Ended
	May 31, 2013 NOK	Jul. 31, 2014 Subsequent Event Petrobras Withholding Taxes USD ($)	Jul. 31, 2014 Subsequent Event Petrobras Withholding Taxes BRL	Jul. 16, 2014 Subsequent Event Norway Tax Assessments Prior to 2012 USD ($) item	Jul. 16, 2014 Subsequent Event Norway Tax Assessments Prior to 2012 NOK	Jul. 02, 2014 Subsequent Event Norway Tax Assessments Prior to 2012 subsidiary item
Subsequent events
Financial claim dropped by the Norwegian authorities	1,800			$ 300	1,800
Number of subsidiaries against which notification of financial claim have been dropped				2	2
Number of subsidiaries acquitted from all criminal charges related to the disclosures in Norwegian tax returns						3
Number of external tax authorities acquitted from all criminal charges related to the disclosures in Norwegian tax returns						2
Contingency related to 3rd party tax assessment		$ 128	283