Special Charges (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) aircraft	Jun. 30, 2015 USD ($)
Property, Plant and Equipment [Line Items]
Payments for Purchase of Other Assets			$ 303,175	$ 308,163
Special charges	$ 8,052	$ 324	$ 24,254	$ 749
Aircraft [Member]
Property, Plant and Equipment [Line Items]
Number of Operating Lease Agreements Terminated | aircraft			3
Airbus A319 [Member] | Aircraft [Member]
Property, Plant and Equipment [Line Items]
Number of Operating Lease Agreements Terminated | aircraft			3
Payments to Acquire Equipment on Lease			$ 65,900
Payments for Purchase of Other Assets			33,800
Noncash or Part Noncash Acquisition, Description			32,100
Fair Value of Assets Acquired			41,200
Special charges			$ 24,258