Income Taxes - Schedule of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Carry forward losses and credits	$ 15,547	$ 7,407
Deferred revenues	13,995	14,226
Accrued payroll, commissions, vacation	1,912	2,685
Equity Compensation	5,737	908
Allowance for doubtful accounts	940	633
Accrued severance pay	297	238
Other	1,346	1,760
Deferred tax assets before valuation allowance	39,774	27,857
Valuation allowance	(39,365)	(27,702)
Deferred tax assets	409	155
Deferred tax liability:
Accrued compensation and other accrued expense	(272)	(289)
Deferred tax liability	(272)	(289)
Net deferred tax asset (liability)	$ 137
Net deferred tax asset (liability)		$ (134)