Long Term Debt (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Debt Instrument [Line Items]
Secured Debt	$ 11,839		$ 12,490
EETC 2012 1A [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	354		0		0
Secured Debt	354
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Debt Instrument, Maturity Date	May 31, 2020
EETC 2012 1B [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	126		0		0
Secured Debt	126
Debt Instrument, Interest Rate, Stated Percentage	6.88%
Debt Instrument, Maturity Date	May 31, 2019
EETC 2011 1A [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		293		0
Secured Debt	253
Debt Instrument, Interest Rate, Stated Percentage	5.30%
Debt Instrument, Maturity Date	Apr. 30, 2019
EETC 2011 1B [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		102		0
Secured Debt	102
Debt Instrument, Interest Rate, Stated Percentage	7.12%
Debt Instrument, Maturity Date	Oct. 31, 2014
EETC 2010 2A [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		204		270
Secured Debt	412
Debt Instrument, Interest Rate, Stated Percentage	4.95%
Debt Instrument, Maturity Date	May 31, 2019
EETC 2010 2B [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		135		0
Secured Debt	135
Debt Instrument, Interest Rate, Stated Percentage	6.75%
Debt Instrument, Maturity Date	Nov. 30, 2015
EETC 2010 1A [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		0		450
Secured Debt	383
Debt Instrument, Interest Rate, Stated Percentage	6.20%
Debt Instrument, Maturity Date	Jul. 31, 2018
EETC 2010 1B [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		100		0
Secured Debt	100
Debt Instrument, Interest Rate, Stated Percentage	6.38%
Debt Instrument, Maturity Date	Jan. 31, 2016
Certificates Issued Prior to 2010 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	0		0		347
Secured Debt	2,449
Certificates [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	480		834		1,067
Secured Debt	$ 4,314	[1],[2]	$ 4,677	[1],[2]

[1] (3) Secured by aircraft.

[2] (2) Due in installments