Goodwill and Other Intangibles (Schedule Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Finite and Indefinite-lived Intangible Assets by Major Class [Line Items]
Incentive to Lessee		$ 120,308	$ 126,007
Amortization of Lease Incentives	$ (5,699)
Finite and Indefinite-lived Intangible Assets [Roll Forward]
Carrying value at beginning of period	111,316
Carrying value at beginning of period	120,316
Amortization expense	(2,644)
Carrying value at end of period	111,316	$ 108,672	$ 111,316
Carrying value at end of period	117,672
ACMI Services [Member] | Airline Certificates [Member]
Finite and Indefinite-lived Intangible Assets [Roll Forward]
Carrying value at beginning of period	9,000
Amortization expense	0
Carrying value at end of period	$ 9,000