Segment Information (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segments	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
REVENUES	$ 404,146	$ 366,073	$ 1,171,217	$ 1,048,832
Deferred Revenue, Revenue Recognized	4,700	500	2,800	2,800
Deferred Revenue	3,400		$ 3,400		$ 3,000
Number of reportable segments (in segments) | segments			2
Interest expense	15,440	16,712	$ 47,808	50,906
Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	404,146	366,073	1,171,217	1,048,832
ACMI Services [Member]
Segment Reporting Information [Line Items]
REVENUES	300,189	272,188	871,958	785,082
Interest expense	4,803	6,530	15,749	19,520
Property, Plant and Equipment, Additions			63,200
ACMI Services [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES		272,171	871,945	784,993
CAM [Member]
Segment Reporting Information [Line Items]
REVENUES	76,268	71,004	225,301	210,610
Interest expense	9,747	9,494	29,709	28,838
Property, Plant and Equipment, Additions			323,400
CAM [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES		$ 42,007	148,104	$ 123,569
Flight Equipment [Member]
Segment Reporting Information [Line Items]
Operating Leases, Future Minimum Payments Receivable, Current	54,900		54,900		186,800
Operating Leases, Future Minimum Payments Receivable, in Two Years	213,000		213,000		178,200
Operating Leases, Future Minimum Payments Receivable, in Three Years	185,000		185,000		152,000
Operating Leases, Future Minimum Payments Receivable, in Four Years	142,700		142,700		110,100
Operating Leases, Future Minimum Payments Receivable, in Five Years	108,200		108,200		75,500
Operating Leases, Future Minimum Payments Receivable, Thereafter	$ 291,400		$ 291,400		$ 186,200