0000100517 2020-04-20 2020-04-21 0000100517 UAL:UnitedAirLinesIncMember 2020-04-20 2020-04-21 iso4217:USD shares iso4217:USD shares 0000100517 false 0000319687 false 8-K 2020-04-21 false false false false 8-K 2020-04-21 UNITED AIRLINES HOLDINGS, INC. UNITED AIRLINES, INC. DE 001-06033 36-2675207 DE 001-10323 74-2099724 233 S. Wacker Drive, Chicago IL 60606 233 S. Wacker Drive, Chicago IL 60606 872 825-4000 872 825-4000 false false false false Common Stock, $0.01 par value UAL NASDAQ false false