Other Assets (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2017 USD ($) Aircraft	Dec. 31, 2016 USD ($)
Property, Plant and Equipment, Number of Aircraft Sold | Aircraft	4
Principal components of other assets
Deferred income tax asset	$ 2,625	$ 1,902
Lease incentives and lease premiums, net of amortization of $44,182 and $39,638, respectively	91,333	96,587
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	97,459	3,834
Deposit Assets	20,915	12,923
Interest Rate Derivative Assets, at Fair Value	3,023	5,735
Other assets	44,054	27,417
Total other assets	259,409	148,398
Amortization of lease incentives and lease premiums	$ 44,182	$ 39,638