Description of Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
United Continental Holdings Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	$ 11	$ 4
United Continental Holdings Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	44	77
United Continental Holdings Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	9	4
United Continental Holdings Inc | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
United Air Lines Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	6	4
United Air Lines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	30	48
United Air Lines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	5	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	5
Continental Airlines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	14	29
Continental Airlines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	4
Continental Airlines Inc | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Designated as Hedging Instrument | Cash Flow Hedging | United Continental Holdings Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	27	77
Designated as Hedging Instrument | Cash Flow Hedging | United Continental Holdings Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	7	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	17	48
Designated as Hedging Instrument | Cash Flow Hedging | United Air Lines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	4	4
Designated as Hedging Instrument | Cash Flow Hedging | Continental Airlines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	10	29
Designated as Hedging Instrument | Cash Flow Hedging | Continental Airlines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	3
Not Designated as Hedging Instrument | United Continental Holdings Inc
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	4
Not Designated as Hedging Instrument | United Continental Holdings Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	17
Not Designated as Hedging Instrument | United Continental Holdings Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
Not Designated as Hedging Instrument | United Continental Holdings Inc | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	2
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	13
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	2
Not Designated as Hedging Instrument | Continental Airlines Inc | Receivables
Derivatives, Fair Value [Line Items]
Fuel contracts due within one year, Assets	4
Not Designated as Hedging Instrument | Continental Airlines Inc | Other Liabilities Current
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	1
Not Designated as Hedging Instrument | Continental Airlines Inc | Other Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Fuel contracts Liabilities	$ 1