Commitments and Contingencies - Future Minimum Lease Payments Under Noncancelable Operating Leases (Details) $ in Thousands	Mar. 31, 2016 USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
remainder of 2016	$ 179,406
Future Minimum Payments Due, 2017	225,134
Future Minimum Payments Due, 2018	207,966
Future Minimum Payments Due, 2019	179,160
Future Minimum Payments Due, 2020	160,977
Future Minimum Payments Due, 2021 and thereafter	557,164
Total minimum lease payments	1,509,807
Aircraft and Spare Engine Leases [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
remainder of 2016	156,000
Future Minimum Payments Due, 2017	197,959
Future Minimum Payments Due, 2018	179,600
Future Minimum Payments Due, 2019	152,236
Future Minimum Payments Due, 2020	141,894
Future Minimum Payments Due, 2021 and thereafter	495,518
Total minimum lease payments	1,323,207
Property Facility Leases [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
remainder of 2016	23,406
Future Minimum Payments Due, 2017	27,175
Future Minimum Payments Due, 2018	28,366
Future Minimum Payments Due, 2019	26,924
Future Minimum Payments Due, 2020	19,083
Future Minimum Payments Due, 2021 and thereafter	61,646
Total minimum lease payments	$ 186,600