STOCK-BASED COMPENSATION PLANS - stock-based compensation expenses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Allocated Share-based Compensation Expense	$ 579	$ 158	$ 1,076	$ 298
Cost of Revenue
Allocated Share-based Compensation Expense	2	5	9	10
Sales and marketing expense
Allocated Share-based Compensation Expense	98	52	127	94
General, and administrative
Allocated Share-based Compensation Expense	$ 479	$ 101	$ 940	$ 194

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Paragraph 1
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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