Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Water abatement Oil Sands [Member]	Jun. 30, 2011 Water abatement Oil Sands [Member]	Dec. 31, 2013 Other Guarantee [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted					$ 96
Payments to Acquire Property, Plant, and Equipment [Abstract]
Commitments to acquire property, plant and equipment	1,270	949
Site Contingency [Line Items]
Site Contingency, Accrual, Undiscounted Amount			$ 29	$ 64