Goodwill and Other Intangibles (Schedule Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Finite and Indefinite-lived Intangible Assets by Major Class [Line Items]
Below Market Lease, Amortization Income, Next Twelve Months				$ 22,600
Incentive to Lessee			$ 63,780	126,007	$ 146,678
Warranted granted adding to lease incentive intangible		$ 100,076
Amortization of Lease Incentives	$ (20,671)	(17,178)
Finite and Indefinite-lived Intangible Assets [Roll Forward]
Carrying value at beginning of period	122,680	135,614
Carrying value at beginning of period	131,680	144,614
Amortization expense	(11,364)	(11,434)
Carrying value at end of period	122,680	135,614	135,614	111,316	$ 122,680
Carrying value at end of period	120,316	131,680	144,614
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months				10,600
Finite-Lived Intangible Assets, Amortization Expense, Year Two				10,600
Finite-Lived Intangible Assets, Amortization Expense, Year Three				10,600
Finite-Lived Intangible Assets, Amortization Expense, Year Four				10,600
Finite-Lived Intangible Assets, Amortization Expense, Year Five				9,800
Below Market Lease, Amortization Income, Year Two				22,700
Below Market Lease, Amortization Income, Year Three				18,100
Below Market Lease, Amortization Income, Year Four				15,100
Below Market Lease, Amortization Income, Year Five				$ 15,200
lease intangible asset reclass		(1,500)
ACMI Services [Member] | Customer Relationships [Member]
Finite and Indefinite-lived Intangible Assets [Roll Forward]
Amortization expense	(11,400)	(11,400)	(2,700)
ACMI Services [Member] | Airline Certificates [Member]
Finite and Indefinite-lived Intangible Assets [Roll Forward]
Carrying value at beginning of period	9,000	9,000
Amortization expense	0	0
Carrying value at end of period	$ 9,000	$ 9,000	$ 9,000