Description of Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
United Continental Holdings Inc
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	$ 3	$ 77
Fuel contracts due within one year, Liabilities	104	4
United Airlines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	2	48
Fuel contracts due within one year, Liabilities	56	4
Continental Airlines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	1	29
Fuel contracts due within one year, Liabilities	$ 48