Debt Instrument, Issuance Price, Percentage

No definition available.

Name:	ual_DebtInstrumentIssuancePricePercentage
Namespace Prefix:	ual_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Quarterly Installment Percentage

+ References

No definition available.

+ Details

Name:	ual_DebtInstrumentQuarterlyInstallmentPercentage
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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Variable Rate Floor

+ References

No definition available.

+ Details

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Namespace Prefix:	ual_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Period Type:	instant

- 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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Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt - Narrative (Details) - USD ($)		12 Months Ended
Debt - Narrative (Details) - USD ($)	Apr. 21, 2021	Dec. 31, 2021
2026 Notes and 2029 Notes \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 4,000,000,000
2026 Notes \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 2,000,000,000
Stated interest rate	4.375%
Issuance price as a percent of principal amount	100.00%
2029 Notes \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 2,000,000,000
Stated interest rate	4.625%
Issuance price as a percent of principal amount	100.00%
PSP2 Note \| Unsecured Debt
Debt Instrument [Line Items]
Aggregate principal amount		$ 870,000,000
Term of debt		10 years
PSP2 Note \| Years One through Five \| Unsecured Debt
Debt Instrument [Line Items]
Stated interest rate		1.00%
PSP2 Note \| Years Six through Ten \| Unsecured Debt \| SOFR
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
PSP3 Note \| Unsecured Debt
Debt Instrument [Line Items]
Aggregate principal amount		$ 810,000,000
Term of debt		10 years
PSP3 Note \| Years One through Five \| Unsecured Debt
Debt Instrument [Line Items]
Stated interest rate		1.00%
PSP3 Note \| Years Six through Ten \| Unsecured Debt \| SOFR
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Term Loan B Facility due 2028 \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 5,000,000,000
Quarterly installment repayment as a percent of the original principal amount	0.25%
Term Loan B Facility due 2028 \| Secured Debt \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.75%
Variable rate floor	0.75%
Term loan \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 1,400,000,000
Term loan \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.49%
Term loan \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		5.25%
CARES Act Term Loan Facility \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 520,000,000
CARES Act Term Loan Facility \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.49%
CARES Act Term Loan Facility \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		5.25%
Borrowings Financing Aircraft Purchases
Debt Instrument [Line Items]
Long term debt		$ 11,200,000,000
Revolving Credit Facility \| Secured Debt \| United Airlines, Inc.
Debt Instrument [Line Items]
Available under revolving credit facility		$ 1,750,000,000
Revolving Credit Facility \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.49%
Revolving Credit Facility \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		5.25%
Revolving Credit Facility \| Senior Secured Revolving Credit Facility due 2025 \| Secured Debt
Debt Instrument [Line Items]
Commitment fee percentage	0.75%
Revolving Credit Facility \| Senior Secured Revolving Credit Facility due 2025 \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%
Revolving Credit Facility \| Senior Secured Revolving Credit Facility due 2025 \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	3.50%
Revolving Credit Facility \| Credit Agreement \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 1,000,000,000