Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
REVENUES	$ 176,549	$ 148,353	$ 353,934	$ 295,378
Net earnings from continuing operations	11,528	10,570	19,699	19,465
EARNINGS FROM DISCONTINUED OPERATIONS, NET OF TAXES	$ 47	$ 214	$ 94	$ 428
Weighted average shares:
Basic (in shares)	63,267	64,541	63,452	64,498
Diluted (in shares)	66,763	65,471	65,910	65,404
Earnings (loss) per share from continuing operations
Basic (in dollars per share)	$ 0.18	$ 0.16	$ 0.31	$ 0.30
Diluted (in dollars per share)	$ 0.12	$ 0.16	$ 0.25	$ 0.30
ACMI Services [Member]
REVENUES	$ 114,145	$ 103,892	$ 229,101	$ 209,360