XML 105 R81.htm IDEA: XBRL DOCUMENT v3.8.0.1

Debt (Parenthetical) (Detail)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017	Jan. 30, 2017
Notes payable, fixed interest rates of 2.88% to 9.52% (weighted average rate of 4.39% as of December 31, 2017), payable through 2028 | United Airlines, Inc. | Secured Debt
Debt Instrument [Line Items]
Weighted average interest rate		4.39%
Debt instrument, maturity date		2028	2028
Notes payable, fixed interest rates of 2.88% to 9.52% (weighted average rate of 4.39% as of December 31, 2017), payable through 2028 | United Airlines, Inc. | Secured Debt | Minimum
Debt Instrument [Line Items]
Debt instrument stated interest rate		2.88%
Notes payable, fixed interest rates of 2.88% to 9.52% (weighted average rate of 4.39% as of December 31, 2017), payable through 2028 | United Airlines, Inc. | Secured Debt | Maximum
Debt Instrument [Line Items]
Debt instrument stated interest rate		9.52%
Notes payable, floating interest rates of the London interbank offered rate ("LIBOR") plus 0.2% to 2.25%, payable through 2028 | United Airlines, Inc. | Secured Debt
Debt Instrument [Line Items]
Debt instrument, maturity date		2028	2028
Notes payable, floating interest rates of the London interbank offered rate ("LIBOR") plus 0.2% to 2.25%, payable through 2028 | United Airlines, Inc. | Secured Debt | LIBOR | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.20%
Notes payable, floating interest rates of the London interbank offered rate ("LIBOR") plus 0.2% to 2.25%, payable through 2028 | United Airlines, Inc. | Secured Debt | LIBOR | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.25%
Term Loan Facility Due 2024 | United Airlines, Inc. | Secured Debt
Debt Instrument [Line Items]
Debt instrument, maturity date		2024
Term Loan Facility Due 2024 | United Airlines, Inc. | Secured Debt | LIBOR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.00%
Term Loan Facility Due 2024 | United Airlines, Inc. | Secured Debt | Certain Market Interest Rates
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.00%
Term Loan Facility Due April 2019 | United Airlines, Inc. | Secured Debt
Debt Instrument [Line Items]
Debt instrument, maturity date		2019	2019
Term Loan Facility Due April 2019 | United Airlines, Inc. | Secured Debt | LIBOR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.50%	2.50%
Term Loan Facility Due April 2019 | United Airlines, Inc. | Secured Debt | Certain Market Interest Rates
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.50%	1.50%
Term Loan Facility Due April 2019 | United Airlines, Inc. | Secured Debt | Interest Rate Floor
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.75%	0.75%
Term Loan Facility Due September 2021 | United Airlines, Inc. | Secured Debt
Debt Instrument [Line Items]
Debt instrument, maturity date		2021	2021
Term Loan Facility Due September 2021 | United Airlines, Inc. | Secured Debt | LIBOR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.75%	2.75%
Term Loan Facility Due September 2021 | United Airlines, Inc. | Secured Debt | Certain Market Interest Rates
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.75%	1.75%
Term Loan Facility Due September 2021 | United Airlines, Inc. | Secured Debt | Interest Rate Floor
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.75%	0.75%
6.375% Senior Notes due 2018
Debt Instrument [Line Items]
Debt instrument stated interest rate		6.375%
6.375% Senior Notes due 2018 | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument stated interest rate	[1]	6.375%	6.375%
Debt instrument, maturity date	[1]	2018	2018
6% Senior Notes due 2020
Debt Instrument [Line Items]
Debt instrument stated interest rate		6.00%
6% Senior Notes due 2020 | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument stated interest rate	[1]	6.00%	6.00%
Debt instrument, maturity date	[1]	2020	2020
4.25% Senior Notes due 2022
Debt Instrument [Line Items]
Debt instrument stated interest rate		4.25%
4.25% Senior Notes due 2022 | United Airlines, Inc.
Debt Instrument [Line Items]
Debt instrument stated interest rate				4.25%
4.25% Senior Notes due 2022 | United Airlines, Inc. | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument stated interest rate	[1]	4.25%	4.25%
Debt instrument, maturity date	[1]	2022	2022
5% Senior Notes due 2024
Debt Instrument [Line Items]
Debt instrument stated interest rate		5.00%
5% Senior Notes due 2024 | United Airlines, Inc.
Debt Instrument [Line Items]
Debt instrument stated interest rate					5.00%
5% Senior Notes due 2024 | United Airlines, Inc. | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument stated interest rate	[1]	5.00%	5.00%
Debt instrument, maturity date	[1]	2024	2024
[1] UAL is the issuer of this debt. United is a guarantor.

X

- Definition

Debt instrument maturity year

+ References

No definition available.

+ Details

Name:	ual_DebtInstrumentMaturityYear
Namespace Prefix:	ual_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_NotesPayableFixedInterestRateOfTwoPointEightEightPercentToNinePointFiveTwoPercentPayableThroughTwoThousandTwentyEightMember
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:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_NotesPayableFloatingInterestRatesOfLiborPlusZeroPointTwoPercentToTwoPointTwoFivePercentPayableThroughTwoThousandTwentyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_TermLoanFacilityDueTwentyTwentyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_VariableRateAxis=ual_CertainMarketInterestRatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_TermLoanFacilityDueAprilTwentyNineteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_VariableRateAxis=ual_FloorRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_TermLoanFacilityDueSeptemberTwentyTwentyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_SixPointThreeSevenFivePercentSeniorNotesDueTwentyEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_SeniorNotesSixPercentDueTwentyTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_FourPointTwoFivePercentSeniorNotesDueTwentyTwentyTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=ual_FivePercentSeniorNotesDueTwentyTwentyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: