REVENUE RECOGNITION, Costs to Obtain or Fulfill a Contract and Significant Judgments when Applying Topic 606 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Costs to Obtain or Fulfill a Contract [Abstract]
Deferred commission expense	$ 3,549		$ 3,649
Significant Judgments when Applying Topic 606 [Abstract]
Accounts and other receivables, net	9,128		13,225
Short term and Long term deferred revenue	21,295	$ 19,785	$ 23,066	$ 19,404
Revenue	17,537	16,374
Commissions [Member]
Significant Judgments when Applying Topic 606 [Abstract]
Revenue	5,211	$ 5,871
ASC 606 [Member]
Costs to Obtain or Fulfill a Contract [Abstract]
Adjustment to retained earnings	139
Reduction in commission expense	(56)
Reduction to deferred commission expense	(1)
Increase in long term deferred commission expense	194
Capitalized sales commissions	5,290
Deferred commission expense	3,549
Long term other assets	1,741
Significant Judgments when Applying Topic 606 [Abstract]
Accounts and other receivables, net	432
Short term and Long term deferred revenue	376
ASC 606 [Member] | Commissions [Member]
Significant Judgments when Applying Topic 606 [Abstract]
Revenue	$ 56