INCOME TAXES - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Deferred revenue	$ 353	$ 492
Inventory capitalization	147	258
Inventory reserves	112	82
Accrued expenses	917	799
Depreciation and amortization	1,506	2,181
Net operating loss	6,549	6,021
Deferred royalty	5	18
Non-cash accounting charges related to stock options and warrants	464	715
Foreign tax credit carryover	5,544	3,797
Other	360	932
Total deferred tax assets	15,957	15,295
Valuation allowance	(11,436)	(8,458)
Total deferred tax assets, net of valuation allowance	4,521	6,837
Deferred tax liabilities:
Prepaid expenses	239	380
Deferred commissions	543	742
Internally-developed software	381	205
Fixed assets	266	178
Total deferred tax liabilities	1,429	1,505
Total net deferred tax assets	3,092	5,332
Canada
Operating Loss Carryforwards [Line Items]
Gross NOL	9
Tax Effected NOL	2
Colombia
Deferred tax assets:
Valuation allowance	(600)	(300)
Operating Loss Carryforwards [Line Items]
Gross NOL	1,641
Tax Effected NOL	558
Cyprus
Operating Loss Carryforwards [Line Items]
Gross NOL	8
Tax Effected NOL	1
Denmark
Operating Loss Carryforwards [Line Items]
Gross NOL	9
Tax Effected NOL	2
Hong Kong
Operating Loss Carryforwards [Line Items]
Gross NOL	110
Tax Effected NOL	18
Japan
Operating Loss Carryforwards [Line Items]
Gross NOL	400
Tax Effected NOL	139
Mexico
Deferred tax assets:
Valuation allowance	(2,800)	(2,400)
Operating Loss Carryforwards [Line Items]
Gross NOL	9,395
Tax Effected NOL	2,819
Norway
Operating Loss Carryforwards [Line Items]
Gross NOL	263
Tax Effected NOL	61
Russia
Operating Loss Carryforwards [Line Items]
Gross NOL	49
Tax Effected NOL	10
Singapore
Operating Loss Carryforwards [Line Items]
Gross NOL	131
Tax Effected NOL	22
South Africa
Deferred tax assets:
Valuation allowance	(100)	0
Operating Loss Carryforwards [Line Items]
Gross NOL	239
Tax Effected NOL	67
Sweden
Deferred tax assets:
Valuation allowance	(100)	(100)
Operating Loss Carryforwards [Line Items]
Gross NOL	549
Tax Effected NOL	121
Switzerland
Deferred tax assets:
Valuation allowance	0	(100)
Operating Loss Carryforwards [Line Items]
Gross NOL	10,893
Tax Effected NOL	1,001
Taiwan
Deferred tax assets:
Valuation allowance	(800)	(1,300)
Operating Loss Carryforwards [Line Items]
Gross NOL	4,707
Tax Effected NOL	800
Ukraine
Deferred tax assets:
Valuation allowance	(100)	(100)
Operating Loss Carryforwards [Line Items]
Gross NOL	604
Tax Effected NOL	109
United Kingdom
Deferred tax assets:
Valuation allowance	(100)	$ 0
Operating Loss Carryforwards [Line Items]
Gross NOL	454
Tax Effected NOL	$ 86