Nonaircraft Rent Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Leases Disclosure [Line Items]
Nonaircraft rent expense	$ 1,278	$ 1,265	$ 839
United Air Lines Inc
Leases Disclosure [Line Items]
Nonaircraft rent expense	654	666	685
Continental Airlines Inc | Successor
Leases Disclosure [Line Items]
Nonaircraft rent expense	624	599	154
Continental Airlines Inc | Predecessor
Leases Disclosure [Line Items]
Nonaircraft rent expense			$ 452