Special Charges (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($) aircraft	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Special charges, non-operating	$ 0	$ 79,412		$ 0	$ 88,613
Special Charges [Abstract]
Special charges	$ 0	$ 174		$ 0	89,342
Airbus A319 [Member] | Capital Lease Obligations [Member]
Special Charges [Abstract]
Purchase price			$ 285,000
Number of aircrafts purchased | aircraft			14
Pilots [Member]
Special Charges [Abstract]
Ratification Incentive					80,700
Adjustments for contractual provisions					8,500
Special charges					$ 89,200