Debt - Additional Information (Detail) (USD $)	6 Months Ended			1 Months Ended			1 Months Ended			1 Months Ended	6 Months Ended			1 Months Ended			12 Months Ended					12 Months Ended	0 Months Ended										1 Months Ended					2 Months Ended			12 Months Ended
	Jun. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Mar. 27, 2013 Term Loan Facility	Mar. 27, 2013 Amended Credit Facility	Dec. 31, 2013 Performance Bonds	Mar. 27, 2013 Revolving Credit Facility	Dec. 31, 2013 Revolving Credit Facility	Jun. 30, 2013 Interest Rate Floor	Nov. 30, 2013 Unsecured Debt	Jun. 30, 2013 LIBOR	Jun. 30, 2013 Certain Market Interest Rates	Dec. 31, 2013 Senior Notes 6.375 Percent Due 2018	May 31, 2013 Senior Notes 6.375 Percent Due 2018 Unsecured Debt	Dec. 31, 2013 6% convertible senior notes due 2029	Dec. 31, 2012 6% convertible senior notes due 2029	Dec. 31, 2013 6% convertible senior notes due 2029 Debtor Optional Redemption Period	Dec. 31, 2013 6% convertible senior notes due 2029 Holder Optional Redemption Period 1	Dec. 31, 2013 6% convertible senior notes due 2029 Holder Optional Redemption Period 2	Dec. 31, 2013 6% convertible senior notes due 2029 Holder Optional Redemption Period 3	Dec. 31, 2013 6.75% senior secured notes due 2015	Dec. 31, 2013 6% Convertible Senior Notes	Feb. 20, 2014 6% Convertible Senior Notes Subsequent Event	Jan. 17, 2014 8% notes due 2024 Subsequent Event	Dec. 31, 2013 United Airlines, Inc.	Dec. 31, 2012 United Airlines, Inc.	Dec. 31, 2013 United Airlines, Inc. Letter of Credit	Dec. 31, 2013 United Airlines, Inc. Letter of Credit and Performance Bonds	Dec. 31, 2013 United Airlines, Inc. Convertible Debt Derivative Asset	Dec. 31, 2012 United Airlines, Inc. Convertible Debt Derivative Asset	Dec. 31, 2013 United Airlines, Inc. Convertible Debt Option Liability	Dec. 31, 2012 United Airlines, Inc. Convertible Debt Option Liability	Jun. 30, 2011 United Airlines, Inc. Unsecured Debt	Dec. 31, 2013 United Airlines, Inc. Adjusted For Embedded Conversion Options		Dec. 31, 2012 United Airlines, Inc. Adjusted For Embedded Conversion Options		Feb. 20, 2014 United Airlines, Inc. Subsequent Event Unsecured Debt	Dec. 31, 2013 United Airlines, Inc. Senior Notes 6.375 Percent Due 2018 Unsecured Debt	Dec. 31, 2012 United Airlines, Inc. Senior Notes 6.375 Percent Due 2018 Unsecured Debt	Dec. 31, 2013 United Airlines, Inc. 6% convertible junior subordinated debentures due 2030 Unsecured Debt	Dec. 31, 2013 United Airlines, Inc. 6% convertible junior subordinated debentures due 2030 Unsecured Debt Convertible Common Stock	Dec. 31, 2013 United Airlines, Inc. 6% convertible junior subordinated debentures due 2030 Unsecured Debt Convertible Preferred Stock	Dec. 31, 2013 United Airlines, Inc. 6.75% senior secured notes due 2015 Secured Debt	Dec. 31, 2012 United Airlines, Inc. 6.75% senior secured notes due 2015 Secured Debt	Aug. 31, 2010 United Airlines, Inc. 6.75% senior secured notes due 2015 Secured Debt	Dec. 31, 2013 United Airlines, Inc. 8% notes due 2024 Unsecured Debt	Dec. 31, 2012 United Airlines, Inc. 8% notes due 2024 Unsecured Debt	Dec. 31, 2013 United Airlines, Inc. Pass Through Certificates	Dec. 31, 2013 United Airlines, Inc. 4.5% convertible notes due 2015 Unsecured Debt	Dec. 31, 2013 United Airlines, Inc. United Five Percentage Convertible Notes Unsecured Debt
Debt Instrument [Line Items]
Aggregate principal amount					$ 1,200,000,000					$ 300,000,000				$ 300,000,000																			$ 726,000,000								$ 248,000,000
Debt instrument maturity date				Apr. 01, 2019			Apr. 01, 2018			Dec. 01, 2020				Jun. 01, 2018																											Nov. 15, 2030
Debt instrument stated interest rate									1.00%	6.00%			6.375%	6.375%	6.00%	6.00%					6.75%												4.50%					4.50%	6.375%	6.375%				6.75%	6.75%	6.75%	8.00%	8.00%
Debt instrument redemption percentage														101.00%
Debt instrument convertible effective interest rate															6.00%							6.00%																			6.00%									4.50%	5.00%
Debt instrument maturity year					2014										2029	2029						2029																2021	2018	2018				2015	2015	2015	2024	2024			2023
Conversion price															$ 8.69																		$ 32.64									$ 57.14	$ 0.875							$ 18.93
Convertible senior notes redemption date																	Oct. 15, 2014	Oct. 15, 2014	Oct. 15, 2019	Oct. 15, 2024
Common stock issued in exchange for convertible notes																						28,000,000	3,582,640
Aggregate principal amount of convertible senior notes exchanged																						240,000,000	31,126,000
Long-term Debt, Gross															104,000,000	345,000,000						104,000,000			11,604,000,000	12,059,000,000													300,000,000					800,000,000	800,000,000	800,000,000	400,000,000	400,000,000
Repurchased debt																																	570,000,000
Debt instrument converted amount																																						156,000,000
Debt instrument conversion rate																																						30.6419
Debt instrument converted shares issued																																						5,000,000
Aggregate principal amount of debt redeemed																								400,000,000
Credit Agreement				900,000,000			1,000,000,000
Available under revolving credit facility								1,000,000,000
Debt instrument, basis spread on variable rate											3.00%	2.00%
Quarterly principal repayment amount	0.25%
Commencement date of installment payment	Jun. 30, 2013
Debt instrument, maturity date	Apr. 01, 2019
Commitment fee percentage	0.75%
Amount utilized to repay term loan				900,000,000
Cash utilized to repay term loan					300,000,000
Credit facility outstanding amount																											61,000,000	398,000,000
Credit facility expiration year						2018
Long term debt		11,708,000,000																							11,604,000,000																								6,000,000,000
Convertible preferred securities, outstanding																																									5,000,000
Liquidation value per preferred security																																									$ 50
Preferred securities liquidation value																									248,000,000
Long-term debt, net		10,171,000,000	10,440,000,000																						10,020,000,000	10,038,000,000								10,067,000,000	[1]	10,095,000,000	[1]
Difference in long term debt noncurrent																									47,000,000	57,000,000
Convertible debt derivative asset																													480,000,000	268,000,000
Convertible debt option liability																															$ 270,000,000	$ 128,000,000

[1] As further described below under "Convertible Debt Securities and Derivatives," there is a basis difference between UAL and United debt values, because we were required to apply different accounting methodologies. The United debt presented above does not agree to United's balance sheet by the amount of this adjustment.