Fair Value Measurements (Fair Value Assets Measured On Nonrecurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2010 Route Authorities [Member]	Dec. 31, 2011 Airport Slots [Member]	Dec. 31, 2010 Nonoperating Aircraft And Spare Engines [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 124	$ 8	$ 128
Loss	$ 29	$ 4	$ 120

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant