SEVERANCE COSTS AND AGREEMENTS WITH EXECUTIVE OFFICERS (Narrative) (Details) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 29, 2016	Jul. 29, 2016	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Severance costs					$ 16	$ 12,996	$ 0
Former President and Chief Executive Officer and Director [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs				$ 2,238
Accelerated compensation cost			$ 1,251
Former President and Chief Executive Officer and Director [Member] | Employment Letter Agreement [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs					5,333
Deferred compensation, liability	$ 1,350
Accelerated compensation cost	2,313
Former President and Chief Executive Officer and Director [Member] | Employment Letter Agreement [Member] | Deferred Bonus [Member]
Restructuring Cost and Reserve [Line Items]
Deferred compensation, liability	475
Former President and Chief Executive Officer and Director [Member] | Employment Letter Agreemen Lump Sum Payment [Member]
Restructuring Cost and Reserve [Line Items]
Deferred compensation, liability	3,214
Former Senior Vice President and Chief Financial Office [Member]
Restructuring Cost and Reserve [Line Items]
Accelerated compensation cost			$ 984
Former Senior Vice President and Chief Financial Office [Member] | Employment Letter Agreement [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs					$ 3,342
Deferred compensation, liability	1,012
Accelerated compensation cost	1,676
Former Senior Vice President and Chief Financial Office [Member] | Employment Letter Agreemen Lump Sum Payment [Member]
Restructuring Cost and Reserve [Line Items]
Deferred compensation, liability	$ 386
Former President US Flag Operatons [Member]
Restructuring Cost and Reserve [Line Items]
Severance costs						2,238
Accelerated compensation cost		$ 789				$ 789
Former President US Flag Operatons [Member] | Employment Letter Agreement [Member]
Restructuring Cost and Reserve [Line Items]
Accelerated compensation cost		$ 23