Entity Central Index Key Entity Central Index Key Entity Address, Address Line One Entity Address, Address Line One Trading Symbol Trading Symbol Entity File Number Entity File Number Soliciting Material Soliciting Material Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Address, Postal Zip Code Entity Address, Postal Zip Code Warrant Warrant [Member] Class of Stock [Domain] Class of Stock [Domain] Entity [Domain] Entity [Domain] City Area Code City Area Code Entities [Table] Entities [Table] Title of 12(b) Security Title of 12(b) Security Amendment Flag Amendment Flag Entity Information [Line Items] Entity Information [Line Items] Security Exchange Name Security Exchange Name Entity Registrant Name Entity Registrant Name Document Period End Date Document Period End Date UNITED AIRLINES, INC United Air Lines Inc [Member] United Airlines, Inc. [Member] Legal Entity [Axis] Legal Entity [Axis] Entity Tax Identification Number Entity Tax Identification Number Common Stock Common Stock [Member] Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Address, City or Town Entity Address, City or Town Class of Stock [Axis] Class of Stock [Axis] Local Phone Number Local Phone Number Written Communications Written Communications Cover [Abstract] Cover [Abstract] Document Type Document Type Entity Emerging Growth Company Entity Emerging Growth Company Entity Address, State or Province Entity Address, State or Province No Trading Symbol Flag No Trading Symbol Flag Pre-commencement Tender Offer Pre-commencement Tender Offer