Summary of Collateral Covenants and Cross Default Provisions (Parenthetical) (Detail) (USD $) In Billions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Credit Agreement
Debt Instrument [Line Items]
Unrestricted liquidity required for credit agreement	$ 3
Minimum ratio of appraised value of collateral for Credit Agreement	1.67
United Air Lines 6% Notes Due 2026
Debt Instrument [Line Items]
Debt instrument stated interest rate	6.00%
Debt instrument maturity year	2026
United Air Lines 6% Notes Due 2028
Debt Instrument [Line Items]
Debt instrument stated interest rate	6.00%
Debt instrument maturity year	2028
Senior Notes 6.375 Percent Due 2018
Debt Instrument [Line Items]
Debt instrument stated interest rate	6.375%
Debt instrument maturity year	2018
Senior Notes 6% Due 2020
Debt Instrument [Line Items]
Debt instrument stated interest rate	6.00%
Debt instrument maturity year	2020
6.75% senior secured notes due 2015
Debt Instrument [Line Items]
Debt instrument stated interest rate	6.75%
Debt instrument maturity year	2015
Debt covenant required collateral coverage ratio	1.5
Additional interest paid if non-compliant on collateral coverage ratio	2.00%