Oil Refinery (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Business Combinations [Abstract]
Business Acquisition, Date of Acquisition Agreement	Jun. 22, 2012
Business Acquisition, Cost of Acquired Entity, Purchase Price	$ 180
Grants Receivable	30
Inventory Exchanged Under Exchange Agreements	$ (1,121)	[1]

[1] Represents value of products exchanged under our buy/sell agreements, as discussed above, determined on a market price basis.