Segment Information (Narrative) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) segments	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
REVENUES	$ 399,358	$ 404,146	$ 377,794	$ 389,277	$ 403,351	$ 366,073	$ 334,576	$ 348,183	$ 1,570,575	$ 1,452,183	$ 892,345
Deferred Revenue, Revenue Recognized									2,800	2,800
Deferred Revenue	3,000				$ 3,000				$ 3,000	3,000
Number of reportable segments (in segments) | segments									2
Interest expense									$ 62,893	66,644	28,799
Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									1,570,575	1,452,183	892,345
ACMI Services [Member]
Segment Reporting Information [Line Items]
REVENUES									1,147,279	1,078,288	548,839
Interest expense									20,542	24,950	6,269
Property, Plant and Equipment, Additions									73,400
ACMI Services [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									1,147,252	1,078,143	548,804
CAM [Member]
Segment Reporting Information [Line Items]
REVENUES									308,661	285,276	228,956
Interest expense									39,304	38,300	21,819
Property, Plant and Equipment, Additions									429,600
CAM [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									205,047	168,106	156,516
Geographic Distribution, Foreign [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									699,200	$ 716,900	$ 231,800
Flight Equipment [Member]
Segment Reporting Information [Line Items]
Operating Leases, Future Minimum Payments Receivable, Current	222,400								222,400
Operating Leases, Future Minimum Payments Receivable, in Two Years	195,500								195,500
Operating Leases, Future Minimum Payments Receivable, in Three Years	150,500								150,500
Operating Leases, Future Minimum Payments Receivable, in Four Years	99,800								99,800
Operating Leases, Future Minimum Payments Receivable, in Five Years	90,700								90,700
Operating Leases, Future Minimum Payments Receivable, Thereafter	$ 202,200								$ 202,200