Description of Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	$ 5	$ 4
Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	51	77
Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	4	4
Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
United Air Lines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	3	4
United Air Lines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	31	48
United Air Lines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2	4
United Air Lines Inc | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Continental Airlines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
Continental Airlines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	20	29
Continental Airlines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
Designated as Hedging Instrument | Cash Flow Hedging | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	7	77
Designated as Hedging Instrument | Cash Flow Hedging | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2	4
Designated as Hedging Instrument | Cash Flow Hedging | United Air Lines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	5	48
Designated as Hedging Instrument | Cash Flow Hedging | United Air Lines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1	4
Designated as Hedging Instrument | Cash Flow Hedging | Continental Airlines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	2	29
Designated as Hedging Instrument | Cash Flow Hedging | Continental Airlines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	3
Not Designated as Hedging Instrument | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	44
Not Designated as Hedging Instrument | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
Not Designated as Hedging Instrument | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Not Designated as Hedging Instrument | United Air Lines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
Not Designated as Hedging Instrument | United Air Lines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	26
Not Designated as Hedging Instrument | United Air Lines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Not Designated as Hedging Instrument | United Air Lines Inc | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Not Designated as Hedging Instrument | Continental Airlines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Not Designated as Hedging Instrument | Continental Airlines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	18
Not Designated as Hedging Instrument | Continental Airlines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	$ 1