GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of goodwill amount
Gross carrying value of goodwill	$ 39,111	$ 39,013	$ 39,054
Accumulated impairment losses	(32,434)	(32,434)	(32,434)
Currency translation adjustments	98	(41)
Balance at the end of the period	6,677	6,579	6,620
MMS
Summary of goodwill amount
Gross carrying value of goodwill	32,434	32,434	32,434
Accumulated impairment losses	(32,434)	(32,434)	(32,434)
Currency translation adjustments	0	0
Balance at the end of the period	0	0	0
ATA
Summary of goodwill amount
Gross carrying value of goodwill	6,677	6,579	6,620
Accumulated impairment losses	0	0	0
Currency translation adjustments	98	(41)
Balance at the end of the period	$ 6,677	$ 6,579	$ 6,620

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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