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Commitments and Contingencies - Firm Commitments and Options to Purchase Aircraft (Details) | Mar. 31, 2021 commitment
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Airbus A321XLR |
Long-term Purchase Commitment [Line Items] |
Number of firm commitments | 50
Scheduled Aircraft Deliveries |
Last Nine Months of 2021 | 0
2022 | 0
After 2022 | 50
Airbus A350 |
Long-term Purchase Commitment [Line Items] |
Number of firm commitments | 45
Scheduled Aircraft Deliveries |
Last Nine Months of 2021 | 0
2022 | 0
After 2022 | 45
Boeing 737 MAX |
Long-term Purchase Commitment [Line Items] |
Number of firm commitments | 180
Scheduled Aircraft Deliveries |
Last Nine Months of 2021 | 13
2022 | 40
After 2022 | 127
Boeing 787 |
Long-term Purchase Commitment [Line Items] |
Number of firm commitments | 9
Scheduled Aircraft Deliveries |
Last Nine Months of 2021 | 9
2022 | 0
After 2022 | 0
Embraer E175 |
Long-term Purchase Commitment [Line Items] |
Number of firm commitments | 4
Scheduled Aircraft Deliveries |
Last Nine Months of 2021 | 4
2022 | 0
After 2022 | 0

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- Definition Number Of Aircrafts Expected To Take Delivery [Abstract] + References No definition available. + Details
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Namespace Prefix: | ual_
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- Definition Number Of Aircrafts Expected To Take Delivery, Remainder Of Year + References No definition available. + Details
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Namespace Prefix: | ual_
Data Type: | xbrli:integerItemType
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- Definition Number Of Aircrafts Expected To Take Delivery, Thereafter + References No definition available. + Details
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- Definition Number Of Aircrafts Expected To Take Delivery, Year Two + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The minimum number of units that must be purchased, in connection with an unconditional purchase obligation that has not been recognized for financial reporting purposes. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
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- Details
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- Details
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