Value of revenue deferred for miles purchased by our business partners that have not been awarded to our frequent flyer loyalty program members. The sale of these miles includes marketing and air transportation components. When our partners award the miles to our program members, the marketing component is recognized as other operating revenue and the air transportation component is transferred to deferred revenue. Used to reflect the noncurrent portion of the liability.

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Debt and Advanced Purchase of Miles (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended			6 Months Ended			3 Months Ended			6 Months Ended
	Jun. 30, 2011	Jul. 31, 2011	Dec. 31, 2010	Jun. 30, 2011 Continental Airlines Inc [Member]	Jun. 30, 2011 United Airlines Inc [Member]	Dec. 31, 2010 United Airlines Inc [Member]	Mar. 31, 2011 UAL 5% Senior Convertible Notes [Member]	Jun. 30, 2011 UAL 4.5% Senior Limited Subordination Convertible Notes [Member]	Jun. 30, 2011 Contingent Senior Unsecured Notes PBGC [Member]	Jun. 30, 2011 Contingent Senior Unsecured Notes PBGC [Member]	Jun. 30, 2011 Continental 6.750% Senior Secured Notes [Member]
Repurchase of senior notes							$ 150	$ 570
Interest rate on notes	8.00%						5.00%	4.50%	8.00%	8.00%	6.75%
Due date of debt instruments							2021	2021		February 14, 2012	2015
Balance of note payable after decrease in long-term debt				210
Increase in advanced purchase of miles	270			270
Increase in other assets	60			60
Maximum obligation under the Co-Brand Agreement secured by junior lien					850
Principal amount of note	500							726
Outstanding principal amount classified as long-term debt								156
UAL's obligation to issue notes to the PBGC, principal									62.5
Net present value of the non-cash obligation, recorded as a liability	49				49				49
Advanced purchase of miles	$ 1,545	$ 165	$ 1,159		$ 1,275	$ 1,159