Additional Repayments Of Debt

No definition available.

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- Definition

Debt Instrument, First Installment Payment Date

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Debt Instrument Floor Interest Rate

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Debt instrument maturity year

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument Quarterly Principal Repayment Percentage

+ References

No definition available.

+ Details

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- Definition

Line Of Credit Facility Terminated

+ References

No definition available.

+ Details

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

- Definition

Minimum Liquidity Amount To Be Maintained Under Credit Agreement

+ References

No definition available.

+ Details

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Namespace Prefix:	ual_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Revolving Credit Facility Appraised Value of Collateral to Outstanding Obligations Ratio

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

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-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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- 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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-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 4: 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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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 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

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Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: 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

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: 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

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- Definition

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

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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 210.5-02.22(a)(1))

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

+ Details

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- Details

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Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

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-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

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+ Details

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Period Type:	duration

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ 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 210.5-02.19(b),22(b))

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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- Definition

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

+ References

+ Details

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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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- Definition

The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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-SubTopic 10

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-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

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- 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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

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-Section 50

-Paragraph 2

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-Name Accounting Standards Codification

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-SubTopic 10

-Section S99

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-Subparagraph (SX 210.3-04)

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

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-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

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Debt - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	6 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended					6 Months Ended		1 Months Ended				1 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 6% Convertible Senior Notes	Sep. 30, 2013 6% Convertible Senior Notes	Feb. 01, 2013 9.875% Senior Notes Due 2013	Feb. 01, 2013 12% Second Lien Due 2013	Feb. 08, 2013 Class B Pass Through Certificates	Apr. 02, 2013 Senior tranche	Jun. 30, 2013 LIBOR	Jun. 30, 2013 Certain Market Interest Rates	May 31, 2013 Unsecured Debt Senior Notes 6 Point 375 Percent Due 2018	Mar. 27, 2013 Term Loan Facility	Mar. 27, 2013 Revolving Credit Facility	Sep. 30, 2013 Revolving Credit Facility	Mar. 27, 2013 Amended Credit Facility
Debt Instrument [Line Items]
Aggregate principal amount							$ 400,000,000	$ 200,000,000	$ 123,000,000	$ 180,000,000			$ 300,000,000				$ 1,200,000,000
Debt instrument maturity date													Jun. 01, 2018	Apr. 01, 2019	Apr. 01, 2018
Debt instrument stated interest rate	8.00%		8.00%	8.00%			9.875%	12.00%					6.375%
Debt instrument effective interest rate					6.00%	6.00%
Common stock issued in exchange for convertible notes	6		28
Aggregate principal amount of senior convertible notes exchanged			240,000,000		51,000,000	240,000,000
Debt instrument maturity year					2029	2029	2013	2013	2013	2013							2014
Outstanding balance of debt instrument					104,000,000	104,000,000
Credit Agreement														900,000,000	1,000,000,000
Available under revolving credit facility																1,000,000,000
Debt instrument, floor rate											1.00%
Debt instrument, basis spread on variable rate											3.00%	2.00%
Quarterly principal repayment amount		0.25%
Commencement date of installment payment		Jun. 30, 2013
Debt instrument, maturity date		Apr. 01, 2019
Commitment fee percentage		0.75%
Unrestricted liquidity requirement			3,000,000,000
Minimum ratio of appraised value of collateral to the outstanding obligations	1.67		1.67
Amount utilized to repay term loan														900,000,000
Cash utilized to repay term loan																	300,000,000
Line of credit maximum borrowing capacity															$ 500,000,000