Subsequent Event (Details) $ in Millions	Oct. 22, 2015 USD ($) aircraft	Sep. 30, 2015 USD ($)
Subsequent Event [Line Items]
Long-term debt		$ 548.2
Airbus A321 [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Number of aircraft delivered \| aircraft	1
Long-term debt	$ 40.4
Debt instruments, blended interest rate	4.15%

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

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-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

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-Section S99

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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

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-Article 7

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