Financial Instruments and Risk Management (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Payments for Premiums on Fuel Option Derivatives	$ 2,100,000
Into-plane fuel cost	108,124,000us-gaap_FuelCostsGrossOfHedging	148,471,000us-gaap_FuelCostsGrossOfHedging
Realized losses (gains) related to fuel derivative contracts	2,607,000us-gaap_GainLossOnSaleOfDerivatives	0us-gaap_GainLossOnSaleOfDerivatives
Unrealized losses (gains) related to fuel derivative contracts	1,695,000us-gaap_UnrealizedGainLossOnDerivatives	0us-gaap_UnrealizedGainLossOnDerivatives
Aircraft fuel	$ 112,426,000us-gaap_FuelCosts	$ 148,471,000us-gaap_FuelCosts

Payments for Premiums on Fuel Option Derivatives

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- Details

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- Definition

Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2(a),(d))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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- Definition

The cost for fuel, incurred during the period, before considering the impacts of any related hedging activities.

+ References

No definition available.

+ Details

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- Definition

The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13(h))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

+ References

+ Details

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