Legal Matters (Details) (SkyWest Airlines and ExpressJet v. Delta, USD $) In Millions, unless otherwise specified	1 Months Ended
	Dec. 31, 2007	Jun. 30, 2013
SkyWest Airlines and ExpressJet v. Delta
Legal Matters
Amount of receivables withheld from weekly scheduled wire payments to SkyWest Airlines and Atlantic Southeast	$ 25
Withheld receivables recognized as revenue by the entity		31.7
Minimum amount of possible damages		0
Reasonably possible loss related to dispute, maximum		$ 25.8