Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Fair Value Adjustment of Warrants	$ 10,800	$ (67,300)	$ 7,700	$ (65,600)
REVENUES	203,607	253,211	406,647	491,128
Net earnings (loss) from continuing operations	24,464	(53,918)	40,146	(44,122)
EARNINGS FROM DISCONTINUED OPERATIONS, NET OF TAXES	$ 170	$ 192	$ 366	$ 384
Weighted average shares:
Basic (in shares)	58,739	59,035	58,790	59,084
Diluted (in shares)	68,363	59,035	68,784	59,084
Earnings per share from continuing operations
Basic (in dollars per share)	$ 0.42	$ (0.91)	$ 0.68	$ (0.75)
Diluted (in dollars per share)	$ 0.21	$ (0.91)	$ 0.48	$ (0.75)
ACMI Services [Member]
REVENUES	$ 119,606	$ 144,499	$ 238,980	$ 289,448