Financial Instruments And Risk Management (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Number of barrels of jet fuel derivative contracts outstanding	22,000,000		22,000,000
Fuel derivative maturity in months	16		16
Derivatives, Fair Value [Line Items]
Collateral Already Posted, Aggregate Fair Value	$ 41		$ 41
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(9)	136	20	237
Price Risk Cash Flow Hedge Derivative, at Fair Value, Net	6		6		80
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer			12
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred			$ 52