Long-term Debt EETCs (Details) $ in Millions	1 Months Ended
Aug. 31, 2015 USD ($) aircraft trust	Jun. 30, 2016 USD ($) aircraft
Enhanced Equipment Trust Certificate [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount \| $		$ 421.3
Enhanced Equipment Trust Certificate [Member] \| Capital Addition Purchase Commitments [Member]
Debt Instrument [Line Items]
Number of pass-through trusts \| trust	2
Debt financing commitments \| $	$ 576.6
Enhanced Equipment Trust Certificate [Member] \| Airbus [Member] \| A320 and A321 [Member]
Debt Instrument [Line Items]
Number of aircraft with secured debt financing commitments scheduled for delivery	15	4
Enhanced Equipment Trust Certificate [Member] \| Airbus [Member] \| A321 [Member]
Debt Instrument [Line Items]
Number of delivered aircraft with secured debt financing commitments		8
Enhanced Equipment Trust Certificate [Member] \| Airbus [Member] \| A320 [Member]
Debt Instrument [Line Items]
Number of delivered aircraft with secured debt financing commitments		3

Face/par value in contract for future debt financing commitments

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- Definition

Number of Aircraft with Secured Debt Financing Commitments Scheduled for Delivery

+ References

No definition available.

+ Details

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- Definition

Number of Delivered Aircraft with Secured Debt Financing Commitments

+ References

No definition available.

+ Details

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- Definition

Number of Trusts

+ References

No definition available.

+ Details

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- 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=64930739&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=64930785&loc=d3e28551-108399

+ Details

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- 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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- Details

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