Actual and Expected Future Amortization Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Actual and Estimated Amortization Expense [Line Items]
Actual Amortization	$ 121	$ 169	$ 96
Projected Amortization:
2013	142
2014	129
2015	106
2016	91
2017	81
United Air Lines Inc
Schedule of Actual and Estimated Amortization Expense [Line Items]
Actual Amortization	55	61	65
Projected Amortization:
2013	52
2014	46
2015	37
2016	34
2017	32
Continental Airlines Inc | Successor
Schedule of Actual and Estimated Amortization Expense [Line Items]
Actual Amortization	66	108	31
Projected Amortization:
2013	90
2014	83
2015	69
2016	57
2017	49
Continental Airlines Inc | Predecessor
Schedule of Actual and Estimated Amortization Expense [Line Items]
Actual Amortization			$ 11