Details about Accumulated Other Comprehensive Income Components (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Salaries And Related Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of unrecognized loss and prior service cost	$ 17	[1]	$ 5	[1],[2]	$ 38	[1]	$ 9	[1],[2]
Fuel Oil Contract | Cash Flow Hedging | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Fuel contracts-reclassifications of losses into earnings	9	[1]	38	[1]	18	[1]	69	[1]
United Airlines, Inc. | Salaries And Related Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of unrecognized loss and prior service cost	17	[1]	5	[1],[2]	38	[1]	9	[1],[2]
United Airlines, Inc. | Income Tax Benefit Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax expense on other comprehensive income					6
United Airlines, Inc. | Fuel Oil Contract | Cash Flow Hedging | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Fuel contracts-reclassifications of losses into earnings	$ 9	[1]	$ 38	[1]	$ 18	[1]	$ 69	[1]

[1] Income tax expense offset by Company's valuation allowance.

[2] This accumulated other comprehensive income component is included in the computation of net periodic pension costs (see Note 5 of this report for additional details.)