Summary of Significant Accounting Policies - Property and Equipment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) aircraft	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Depreciation, Depletion and Amortization, Nonproduction [Abstract]
Depreciation	$ 30,797	$ 11,169	$ 8,340
Amortization of heavy maintenance	43,111	35,802	23,607
Total depreciation and amortization	73,908	46,971	31,947
Amortization of capitalized software costs	$ 3,100	3,500	3,700
Aircraft
Property, Plant and Equipment [Line Items]
Number of aircraft under operating lease | aircraft	61
Aircrafts, Major Spare Rotable Parts, Avionics, and Assemblies [Member]
Property, Plant and Equipment [Line Items]
Residual value, percentage	10.00%
Aircraft
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	25 years
Number of aircraft capitalized | aircraft	18
Aircraft | Minimum
Property, Plant and Equipment [Line Items]
Operating leases, term	3 years
Aircraft | Maximum
Property, Plant and Equipment [Line Items]
Operating leases, term	15 years
Spare rotables and flight assemblies | Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	7 years
Spare rotables and flight assemblies | Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	15 years
Other equipment and vehicles | Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	5 years
Other equipment and vehicles | Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	7 years
Internal use software
Depreciation, Depletion and Amortization, Nonproduction [Abstract]
Capitalized computer software, net	$ 8,800	7,400
Capitalized software costs during the year	$ 4,300	$ 2,700	$ 7,000
Internal use software | Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	3 years
Internal use software | Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives used for the principal depreciable asset classifications	10 years
Spare engines | Minimum
Property, Plant and Equipment [Line Items]
Operating leases, term	7 years
Spare engines | Maximum
Property, Plant and Equipment [Line Items]
Operating leases, term	12 years