XML 83 R88.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Subsequent Events (Details) - Subsequent Event | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Feb. 24, 2020
China |  |
Subsequent Event [Line Items] |  |
Decline in near-term demand due to Level 4 travel advisory |  | 100.00%
China | Forecast |  |
Subsequent Event [Line Items] |  |
Percent of planned capacity impacted by Level 4 travel advisory | 5.00% |
Other Trans-Pacific Countries |  |
Subsequent Event [Line Items] |  |
Decline in near-term demand due to Level 4 travel advisory |  | 75.00%
Other Trans-Pacific Countries | Forecast |  |
Subsequent Event [Line Items] |  |
Percent of planned capacity impacted by Level 4 travel advisory | 10.00% |

X
- Definition Increase (Decrease) In Demand Due To Travel Restrictions + References No definition available. + Details
Name: | ual_IncreaseDecreaseInDemandDueToTravelRestrictionsPercent
Namespace Prefix: | ual_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percent Of Planned Capacity Impacted By Travel Advisory + References No definition available. + Details
Name: | ual_PercentOfPlannedCapacityImpactedByTravelAdvisory
Namespace Prefix: | ual_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_StatementGeographicalAxis=country_CN
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=ual_TransPacificCountriesExcludingChinaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |