Oil Refinery (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total operating revenue	$ 8,500		$ 8,413
Operating Income (Loss)	222		382
Interest Expense	178
Depreciation and Amortization	405		386
Assets	45,068			44,550
Segment Reporting Information, Expenditures for Additions to Long-Lived Assets	647
Airline [Member]
Segment Reporting Information [Line Items]
Total operating revenue	8,500
Operating Income (Loss)	244
Interest Expense	178
Depreciation and Amortization	401
Assets	43,789
Segment Reporting Information, Expenditures for Additions to Long-Lived Assets	641
Refinery [Member]
Segment Reporting Information [Line Items]
Total operating revenue	1,731
Operating Income (Loss)	(22)
Interest Expense	0
Depreciation and Amortization	4
Assets	1,279
Segment Reporting Information, Expenditures for Additions to Long-Lived Assets	6
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Intersegment Revenue	(292)	[1]
Inventory Exchanged Under Exchange Agreements	(1,321)	[2]
Revenue from External Customers	$ (118)	[3]

[1] Represents transfers, valued on a market price basis, from the refinery to the airline segment for use in airline operations. We determine market price by reference to the market index for the primary delivery location for jet fuel from the refinery, which is New York harbor.

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

[3] Represents sales of refinery by-products to third parties. Such products are generally sold at or near cost; accordingly, margin on such sales is de minimis. By-products are produced as a result of the refining of crude oil into gasoline, diesel and jet fuel.