Special Charges (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Debt Instrument [Line Items]
Number of mechanics offering to retire early	400
Number of flight attendants voluntarily on leave	1,800
Accrual severance and medical costs	$ 1,139	$ 1,509	$ 81
Number of aircraft sold	6
Continental Airlines Inc [Member]
Debt Instrument [Line Items]
Accrual severance and medical costs	350	521
UAL [Member]
Debt Instrument [Line Items]
Accrual severance and medical costs	90
United Airlines Inc [Member]
Debt Instrument [Line Items]
Accrual severance and medical costs	789	988
Accrual balance of future lease	$ 23		$ 38