Variable Interest Entities (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Feb. 29, 2020 USD ($) Aircraft	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Aircraft Term_Loan Entity	Jun. 30, 2019 USD ($)
Variable Interest Entity [Line Items]
Gain (Loss) on Extinguishment of Debt | $		$ 65	$ 0	$ 4,020	$ 0
Number of Aircraft Impaired | Aircraft				20
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of Consolidated Variable Interest Entities | Entity				2
Number of Aircrafts | Aircraft				2
Variable Interest Entity, Primary Beneficiary [Member] | Air Knight VIEs | ECA Term Financings
Variable Interest Entity [Line Items]
Type of term loans | Term_Loan				6
Debt instrument, term				12 years
Net book value of flight equipment held for lease | $		124,432		$ 124,432
Consolidated debt outstanding | $		$ 44,860		$ 44,860
South African Airways [Member]
Variable Interest Entity [Line Items]
Number of Aircraft Impaired | Aircraft	4
South African Airways [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Air Knight VIEs | ECA Term Financings
Variable Interest Entity [Line Items]
Repayments of Debt | $	$ 95,128
Number of Aircraft Impaired | Aircraft	4