Oil Refinery (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Combinations [Abstract]
Business Acquisition, Date of Acquisition Agreement									Jun. 22, 2012
Business Acquisition, Cost of Acquired Entity, Purchase Price					$ 180					$ 180
Grants Receivable					30					30
Total Operating Revenue	$ 9,076	$ 10,490	$ 9,707	$ 8,500	$ 8,602	$ 9,923	$ 9,732	$ 8,413	$ 37,773	$ 36,670	$ 35,115