Commitments and Contingencies - Future Minimum Lease Payments Under Noncancelable Operating Leases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015 leases
Capital Leases, Future Minimum Payments, Net Minimum Payments, Rolling Maturity [Abstract]
remainder of 2015	1,033
Future Minimum Payments Due, 2016	1,044
Future Minimum Payments Due, 2017	44
Future Minimum Payments Due, 2018	44
Future Minimum Payments Due, 2019	12
Future Minimum Payments Due, 2020 and thereafter	0
Total minimum lease payments	2,177
Less amount representing interest	150
Present value of minimum lease payments	2,027
Less current portion	1,226us-gaap_CapitalLeaseObligationsCurrent
Long-term portion	801
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
remainder of 2015	184,572
Future Minimum Payments Due, 2016	238,152
Future Minimum Payments Due, 2017	221,941
Future Minimum Payments Due, 2018	198,164
Future Minimum Payments Due, 2019	167,912
Future Minimum Payments Due, 2020 and thereafter	678,929
Total minimum lease payments	1,689,670
Aircraft and Spare Engine Leases [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
remainder of 2015	160,914
Future Minimum Payments Due, 2016	212,554
Future Minimum Payments Due, 2017	196,048
Future Minimum Payments Due, 2018	172,341
Future Minimum Payments Due, 2019	144,229
Future Minimum Payments Due, 2020 and thereafter	592,465
Total minimum lease payments	1,478,551
Property Facility Leases [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
remainder of 2015	23,658
Future Minimum Payments Due, 2016	25,598
Future Minimum Payments Due, 2017	25,893
Future Minimum Payments Due, 2018	25,823
Future Minimum Payments Due, 2019	23,683
Future Minimum Payments Due, 2020 and thereafter	86,464
Total minimum lease payments	211,119
Quick Engine Change Kit [Member]
Capital Leased Assets [Line Items]
Number of Capital Leases	2
Capital Leases of Lessee, Lease Term	3 years

Capital Leases of Lessee, Lease Term

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The number of units (items of property) under capital lease arrangements.

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Amount of capital lease obligation due within 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 19

-Article 5

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

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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-Subparagraph (SX 210.5-02.20)

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid more than one year (or one operating cycle, if longer) after the balance sheet date.

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

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-Paragraph 22

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Amount of minimum lease payments for capital leases.

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Amount of minimum lease payments for capital leases due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount necessary to reduce net minimum lease payments to present value for capital leases.

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Present value of minimum lease payments for capital leases net of executory costs, including amounts paid by the lessee to the lessor for insurance, maintenance and taxes.

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Amount of minimum lease payments for capital leases due in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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