Segment Information (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segments	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
REVENUES	$ 377,794	$ 334,576	$ 767,071	$ 682,759
Deferred Revenue, Revenue Recognized	1,600	600	2,800	2,800
Deferred Revenue	4,900		$ 4,900		$ 3,000
Number of reportable segments (in segments) | segments			2
Interest expense	16,045	16,804	$ 32,368	34,194
Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	377,794	334,576	767,071	682,759
ACMI Services [Member]
Segment Reporting Information [Line Items]
REVENUES	287,604	254,938	571,769	512,894
Interest expense	5,645	6,441	10,946	12,990
Property, Plant and Equipment, Additions			41,700
ACMI Services [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES		254,869	571,756	512,822
CAM [Member]
Segment Reporting Information [Line Items]
REVENUES	74,870	69,256	149,033	139,606
Interest expense	9,707	9,379	19,962	19,344
Property, Plant and Equipment, Additions			220,500
CAM [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES		$ 39,953	96,695	$ 81,562
Flight Equipment [Member]
Segment Reporting Information [Line Items]
Operating Leases, Future Minimum Payments Receivable, Current	97,900		97,900		186,800
Operating Leases, Future Minimum Payments Receivable, in Two Years	188,600		188,600		178,200
Operating Leases, Future Minimum Payments Receivable, in Three Years	162,000		162,000		152,000
Operating Leases, Future Minimum Payments Receivable, in Four Years	120,100		120,100		110,100
Operating Leases, Future Minimum Payments Receivable, in Five Years	85,600		85,600		75,500
Operating Leases, Future Minimum Payments Receivable, Thereafter	$ 214,200		$ 214,200		$ 186,200