Basis of Presentation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Change in Accounting Estimate [Line Items]
Change in accounting estimate, financial effect on net income, spoilage adjustment	$ 22		$ 45
Prior Period Adjustment [Abstract]
Prior Period Reclassification Adjustment		$ (19)		$ (31)
Change in Spoilage Estimate [Domain]
Change in Accounting Estimate [Line Items]
Change in Accounting Estimate Financial Effect on Passenger Revenue, Spoilage Estimate	$ 41		$ 85
Change in accounting estimate,financial effect on earnings per share	$ 0.03		$ 0.07