Goodwill and Other Intangibles (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill, Acquired During Period	$ 353,466
Goodwill [Roll Forward]
Carrying value, beginning balance	390,745	$ 37,279	$ 37,133
Purchase Price Adjustment to Goodwill		146
Carrying value, ending balance	390,745	37,279
ACMI Services [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	234,571
Goodwill [Roll Forward]
Carrying value, beginning balance	234,571
Carrying value, ending balance	234,571
CAM [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	118,895
Goodwill [Roll Forward]
Carrying value, beginning balance	153,290	34,395	34,395
Carrying value, ending balance	153,290	34,395
MRO Services [Member] [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Carrying value, beginning balance	2,884	2,884	$ 2,738
Purchase Price Adjustment to Goodwill		146
Carrying value, ending balance	$ 2,884	$ 2,884