GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Summary of goodwill amount
Goodwill	$ 39,013	$ 39,013
Accumulated impairment losses	(32,434)	(32,434)
Balance at December 31, 2016	6,579
Accumulated impairment losses	62
Balance at September 30, 2017	6,641
MMS
Summary of goodwill amount
Goodwill	32,434	32,434
Accumulated impairment losses	(32,434)	(32,434)
Balance at December 31, 2016	0
Accumulated impairment losses	0
Balance at September 30, 2017	0
ATA
Summary of goodwill amount
Goodwill	6,579	6,579
Accumulated impairment losses	0	$ 0
Balance at December 31, 2016	6,579
Accumulated impairment losses	62
Balance at September 30, 2017	$ 6,641