Available for Sale Investment Maturity Term

No definition available.

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- Definition

Fair Value [Line Items]

+ References

No definition available.

+ Details

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- Definition

Initial Commitments from Company and Other Corporate Investors, Amount

+ References

No definition available.

+ Details

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

+ Details

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481664/323-10-45-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(10))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 25
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-25

+ Details

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Balance Type:	debit
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- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479536/321-10-50-3

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Balance Type:	debit
Period Type:	instant

- Definition

Number of aircraft operated by the carrier.

+ References

No definition available.

+ Details

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- Details

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- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ual_RepublicAirwaysHoldingsIncMember
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- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ual_UnitedAirlinesVenturesSustainableFlightFundMember
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- Details

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Financial Instruments and Fair Value Measurements - Narrative (Details) $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($) aircraft	Mar. 31, 2023 USD ($)
Fair Value [Line Items]
Equity method investments	$ 214
CommuteAir LLC
Fair Value [Line Items]
Ownership stake	40.00%
Number of aircraft operated \| aircraft	56
Republic Airways Holdings Inc.
Fair Value [Line Items]
Ownership stake	19.00%
Number of aircraft operated \| aircraft	66
United Airlines Ventures Sustainable Flight Fund
Fair Value [Line Items]
Ownership stake	49.99%
Initial commitment		$ 100
Blue Blade Energy, LLC
Fair Value [Line Items]
Ownership stake	20.00%
Fulcrum BioEnergy, Inc., Boom, Alder Fuels LLC, Heart Aerospace Incorporated and ZeroAvia, Inc.
Fair Value [Line Items]
Investment carrying value	$ 417
Corporate Debt \| Maximum
Fair Value [Line Items]
Available-for-sale securities remaining maturities	2 years