Lease Obligations (Narrative) (Details) (USD $) In Billions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Leases [Abstract]
Number Of Aircraft Under Capital Leases	111
Number Of Aircraft Under Operating Leases	90
No of contract carriers aircraft under operating lease	550
Operating Leases, Rent Expense	$ 1.1	$ 1.2	$ 1.3

Rental expense incurred for leased assets including furniture and equipment which has not been recognized in costs and expenses applicable to sales and revenues; for example, cost of goods sold or other operating costs and expenses.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration