Earnings Per Share (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011
UAL 6% Senior Convertible Notes [Member]
Interest rate of senior notes		6.00%
Expiration date		2031
Principal amount of senior notes	$ 633	$ 633
Redeemed rate of senior note		100.00%
UAL 4.5% Senior Limited Subordination Convertible Notes [Member]
Interest rate of senior notes		4.50%
Expiration date		2021
Principal amount of senior notes	726	726
Repurchase of senior notes	$ 570