XML 73 R49.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Debt - Details of Pass Through Trusts (Details) - USD ($) $ in Millions | 6 Months Ended
--- | ---
Jun. 30, 2018 | Jun. 30, 2017
Debt Instrument [Line Items] |  |
Total proceeds received from issuance of debt during 2018 and recorded as debt as of June 30, 2018 | $ 1,308 | $ 1,139
United Airlines, Inc. |  |
Debt Instrument [Line Items] |  |
Principal | 1,161 |
Total proceeds received from issuance of debt during 2018 and recorded as debt as of June 30, 2018 | 1,308 | $ 1,139
United Airlines, Inc. | Class AA Pass Through Certificates | February 2018 |  |
Debt Instrument [Line Items] |  |
Principal | $ 677 |
Stated interest rate | 3.50% |
Total proceeds received from issuance of debt during 2018 and recorded as debt as of June 30, 2018 | $ 677 |
United Airlines, Inc. | Class A Pass Through Certificates | February 2018 |  |
Debt Instrument [Line Items] |  |
Principal | $ 258 |
Stated interest rate | 3.70% |
Total proceeds received from issuance of debt during 2018 and recorded as debt as of June 30, 2018 | $ 258 |
United Airlines, Inc. | Class B Pass Through Certificates | May 2018 |  |
Debt Instrument [Line Items] |  |
Principal | $ 226 |
Stated interest rate | 4.60% |
Total proceeds received from issuance of debt during 2018 and recorded as debt as of June 30, 2018 | $ 226 |
United Airlines, Inc. | Pass Through Certificates |  |
Debt Instrument [Line Items] |  |
Total proceeds received from issuance of debt during 2018 and recorded as debt as of June 30, 2018 | $ 1,161 |

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ual_ClassAAPassThroughCertificatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ual_PeriodAxis=ual_FebruaryTwentyEighteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ual_ClassAPassThroughCertificatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ual_ClassBPassThroughCertificatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ual_PeriodAxis=ual_MayTwentyEighteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ual_PassThroughCertificatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |