Amounts Recognized in Consolidated Balance Sheet and Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits
Amounts recognized in the consolidated balance sheets consist of:
Noncurrent asset	$ 35	$ 31
Current liability	(4)	(9)
Noncurrent liability	(2,400)	(1,862)
Total liability	(2,369)	(1,840)
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	(826)	(231)
Prior service cost	2	3
Total accumulated other comprehensive income (loss)	(824)	(228)
Pension Benefits | United Air Lines Inc
Amounts recognized in the consolidated balance sheets consist of:
Noncurrent asset	35	31
Current liability		(3)
Noncurrent liability	(97)	(92)
Total liability	(62)	(64)
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	(22)	(10)
Prior service cost	15	18
Total accumulated other comprehensive income (loss)	(7)	8
Pension Benefits | Continental Airlines Inc
Amounts recognized in the consolidated balance sheets consist of:
Current liability	(4)	(6)
Noncurrent liability	(2,303)	(1,770)
Total liability	(2,307)	(1,776)
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	(804)	(221)
Prior service cost	(13)	(15)
Total accumulated other comprehensive income (loss)	(817)	(236)
Other Postretirement Benefits
Amounts recognized in the consolidated balance sheets consist of:
Current liability	(71)	(76)
Noncurrent liability	(2,614)	(2,407)
Total liability	(2,685)	(2,483)
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	(79)	33
Prior service cost	(24)	(2)
Total accumulated other comprehensive income (loss)	(103)	31
Other Postretirement Benefits | United Air Lines Inc
Amounts recognized in the consolidated balance sheets consist of:
Current liability	(61)	(60)
Noncurrent liability	(2,384)	(2,115)
Total liability	(2,445)	(2,175)
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	(80)	46
Prior service cost	(24)	(2)
Total accumulated other comprehensive income (loss)	(104)	44
Other Postretirement Benefits | Continental Airlines Inc
Amounts recognized in the consolidated balance sheets consist of:
Current liability	(10)	(16)
Noncurrent liability	(230)	(292)
Total liability	(240)	(308)
Amounts recognized in accumulated other comprehensive income (loss) consist of:
Net actuarial gain (loss)	1	(13)
Total accumulated other comprehensive income (loss)	$ 1	$ (13)