XML 100 R61.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Income Taxes - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Income Taxes [Line Items] |  |  |
Capital loss carryforwards, valuation allowance | $ 150 |  |
Unrecognized tax benefits | 66 | $ 58 | $ 55
Federal |  |  |
Income Taxes [Line Items] |  |  |
Tax credits | 50 |  |
Federal | United Airlines, Inc. |  |  |
Income Taxes [Line Items] |  |  |
NOL carryforwards | 12,000 |  |
Tax effected amount of NOLs | 2,500 |  |
NOLs without an expiration date | $ 11,600 |  |
Federal | Minimum |  |  |
Income Taxes [Line Items] |  |  |
Tax credit expiration period | 1 year |  |
Federal | Maximum |  |  |
Income Taxes [Line Items] |  |  |
Tax credit expiration period | 20 years |  |
Federal | 2029 | United Airlines, Inc. |  |  |
Income Taxes [Line Items] |  |  |
NOL carryforwards | $ 200 |  |
Federal | 2033 | United Airlines, Inc. |  |  |
Income Taxes [Line Items] |  |  |
NOL carryforwards | 200 |  |
State |  |  |
Income Taxes [Line Items] |  |  |
Tax credits | 56 |  |
NOL and tax credit carryforwards, valuation allowance | 29 |  |
State | United Airlines, Inc. |  |  |
Income Taxes [Line Items] |  |  |
NOL carryforwards | 3,400 |  |
Tax effected amount of NOLs | $ 200 |  |
State | Minimum |  |  |
Income Taxes [Line Items] |  |  |
Tax credit expiration period | 1 year |  |
State | Minimum | United Airlines, Inc. |  |  |
Income Taxes [Line Items] |  |  |
NOL expiration period | 1 year |  |
State | Maximum |  |  |
Income Taxes [Line Items] |  |  |
Tax credit expiration period | 15 years |  |
State | Maximum | United Airlines, Inc. |  |  |
Income Taxes [Line Items] |  |  |
NOL expiration period | 20 years |  |

X
- Definition Capital Loss Carryforwards, Valuation Allowance + References No definition available. + Details
Name: | ual_CapitalLossCarryforwardsValuationAllowance
Namespace Prefix: | ual_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Income Taxes [Line Items] + References No definition available. + Details
Name: | ual_IncomeTaxesLineItems
Namespace Prefix: | ual_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operating Loss Carryforwards And Tax Credit Carryforwards, Valuation Allowance + References No definition available. + Details
Name: | ual_OperatingLossCarryforwardsAndTaxCreditCarryforwardsValuationAllowance
Namespace Prefix: | ual_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Operating Loss Carryforwards, Expiration Period + References No definition available. + Details
Name: | ual_OperatingLossCarryforwardsExpirationPeriod
Namespace Prefix: | ual_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operating Loss Carryforwards, Tax Effected Amount + References No definition available. + Details
Name: | ual_OperatingLossCarryforwardsTaxEffectedAmount
Namespace Prefix: | ual_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Tax Credit Carryforward, Expiration Period + References No definition available. + Details
Name: | ual_TaxCreditCarryforwardExpirationPeriod
Namespace Prefix: | ual_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are not subject to expiration dates. + References No definition available. + Details
Name: | us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-3 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-3 + Details
Name: | us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 15A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-15A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 10B -Publisher FASB -URI https://asc.fasb.org//1943274/2147482525/740-10-45-10B + Details
Name: | us-gaap_UnrecognizedTaxBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ual_UnitedAirLinesIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ual_NetOperatingLossCarryforwardByExpirationAxis=ual_NetOperatingLossCarryForwardExpirationYear2029Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ual_NetOperatingLossCarryforwardByExpirationAxis=ual_NetOperatingLossCarryForwardExpirationYear2033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |