Debt instrument maturity year

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Write off of unamortized discount.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ 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)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

+ Details

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

- 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=34725769&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=6451184&loc=d3e28551-108399

+ 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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ References

+ Details

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

- Definition

Number of shares issued during the period as a result of the conversion of convertible securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29-30)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

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-Section 50

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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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-Name Accounting Standards Codification

-Topic 505

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-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

+ Details

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Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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- Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=ual_SixPercentNotesDueTwentyTwentySixAndTwentyTwentyEightMember
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Balance Type:
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- Details

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- Details

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- Details

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- Details

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Debt - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions			1 Months Ended	3 Months Ended		9 Months Ended
	May. 01, 2015	Apr. 01, 2015	Jan. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Unsecured Debt \| 4.5% Convertible Notes Due 2015
Debt Instrument [Line Items]
Debt instrument stated interest rate			4.50%			4.50%
Long-term Debt, Gross			$ 202			$ 202
Common stock issued in exchange for convertible notes			11			11
Debt instrument maturity year			2015
United Airlines, Inc.
Debt Instrument [Line Items]
Borrowed principal amount						$ 480
United Airlines, Inc. \| Minimum
Debt Instrument [Line Items]
Debt instrument maturity year						2025
United Airlines, Inc. \| Maximum
Debt Instrument [Line Items]
Debt instrument maturity year						2027
United Airlines, Inc. \| 6% Notes due 2026 and 2028
Debt Instrument [Line Items]
Write off of unamortized discount				$ 128
United Airlines, Inc. \| Unsecured Debt \| 4.5% Convertible Notes Due 2015
Debt Instrument [Line Items]
Debt instrument stated interest rate						4.50%
Long-term Debt, Gross			$ 202				$ 202
Common stock issued in exchange for convertible notes			11
Debt instrument maturity year						2015
United Airlines, Inc. \| Unsecured Debt \| 6% Notes Due 2026
Debt Instrument [Line Items]
Debt instrument stated interest rate					6.00%
Debt instrument maturity year					2026
Debt purchased and retired		$ 303			$ 18
United Airlines, Inc. \| Unsecured Debt \| 6% Notes Due 2028
Debt Instrument [Line Items]
Debt instrument stated interest rate					6.00%
Debt instrument maturity year					2028
Debt purchased and retired	$ 298				$ 13
United Airlines, Inc. \| Secured Debt \| Revolving Credit Facility
Debt Instrument [Line Items]
Available under revolving credit facility						$ 1,350