Revenues, Recognition and Allowances (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	[1]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 16,232		$ 16,232		$ 18,143
Accrued expenses	9,269		9,269		$ 13,502
Revenue, net	16,751	$ 18,408	31,296	$ 38,299
Cost of revenues	$ 11,728	$ 10,371	$ 21,053	$ 19,328
Gross margin	30.00%		33.00%
Balance Without Adoption of New Revenue Standard
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 18,144		$ 18,144
Accrued expenses	11,181		11,181
Revenue, net	17,228		32,408
Cost of revenues	$ 12,205		$ 22,165
Gross margin	29.00%		32.00%
Effect of Change Increase/(Decrease) | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ (1,912)		$ (1,912)
Accrued expenses	(1,912)		(1,912)
Revenue, net	(477)		(1,112)
Cost of revenues	$ (477)		$ (1,112)
Gross margin	(1.00%)		(1.00%)

[1] Derived from the audited December 31, 2017 financial statement