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