XML 48 R34.htm IDEA: XBRL DOCUMENT
v3.20.2

Revenue - Roll Forward of Frequent Flyer Deferred Revenue (Details) - Frequent Flyer - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Frequent Flyer Deferred Revenue [Roll Forward] |  |  |  |
Total Frequent flyer deferred revenue - beginning balance | $ 5,670 | $ 5,198 | $ 5,276 | $ 5,005
Total miles awarded | 268 | 662 | 1,056 | 1,951
Travel miles redeemed (Passenger revenue) | (87) | (607) | (444) | (1,634)
Non-travel miles redeemed (Other operating revenue) | (16) | (34) | (53) | (103)
Total Frequent flyer deferred revenue - ending balance | $ 5,835 | $ 5,219 | $ 5,835 | $ 5,219

X
- Definition Frequent flyer mileage miles awarded in period. + References No definition available. + Details
Name: | ual_FrequentFlyerMileageMilesAwardedInPeriod
Namespace Prefix: | ual_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Movement In Contract With Customer Liability [Roll Forward] + References No definition available. + Details
Name: | ual_MovementInContractWithCustomerLiabilityRollForward
Namespace Prefix: | ual_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Non-travel miles redemption, frequent flyer deferred revenue. + References No definition available. + Details
Name: | ual_NonTravelMilesRedemptionFrequentFlyerDeferredRevenue
Namespace Prefix: | ual_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Travel miles redemption, frequent flyer deferred revenue. + References No definition available. + Details
Name: | ual_TravelMilesRedemptionFrequentFlyerDeferredRevenue
Namespace Prefix: | ual_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130531-203044 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130532-203044 + Details
Name: | us-gaap_ContractWithCustomerLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | srt_ProductOrServiceAxis=ual_FrequentFlyerProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |