Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value Adjustment of Warrants	$ (15,600)	$ (8,800)	$ 5,800	$ (400)					$ (19,100)
REVENUES	221,675	193,261	176,549	177,385	$ 181,581	$ 142,305	$ 148,353	$ 147,025	768,870	$ 619,264	$ 589,592
Income (Loss) from Continuing Operations before Interest Expense, Interest Income, Income Taxes, Extraordinary Items, Noncontrolling Interests, Net	18,140	14,456	15,801	15,351	22,550	12,917	19,794	17,529
Net earnings from continuing operations	(755)	2,116	11,528	8,171	13,343	6,347	10,570	8,895	21,060	39,155	32,074
EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAXES	$ 2,287	$ 47	$ 47	$ 47	$ 1,425	$ 214	$ 214	$ 214	$ 2,428	$ 2,067	$ (2,214)
Weighted average shares:
Basic (in shares)	59,083	59,379	63,267	63,636	63,742	64,239	64,541	64,454	61,330	64,242	64,253
Diluted (in shares)	59,083	60,283	66,763	65,057	64,536	65,171	65,471	65,337	62,994	65,127	65,211
Earnings per share from continuing operations
Basic (in dollars per share)	$ (0.01)	$ 0.04	$ 0.18	$ 0.13	$ 0.21	$ 0.10	$ 0.16	$ 0.14	$ 0.34	$ 0.61	$ 0.50
Diluted (in dollars per share)	$ (0.01)	$ 0.04	$ 0.12	$ 0.13	$ 0.21	$ 0.10	$ 0.16	$ 0.14	$ 0.33	$ 0.60	$ 0.49
Pension Plans [Member]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements									$ 0	$ 0	$ (11,660)
Pension Plans [Member] | Continuing Operations [Member]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements											6,700
Pension Plans [Member] | Discontinued Operations [Member]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements											4,960
ACMI Services [Member]
REVENUES									$ 492,859	$ 433,109	$ 439,919