Annual report pursuant to Section 13 and 15(d)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)

v3.8.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
USD ($)
ر.س / $
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Trade Receivables and Allowance for Doubtful Accounts [Abstract]        
Increase in allowance for doubtful accounts   $ 0 $ 90 $ 0
Accounts receivable written off   $ 0 $ 93 $ 0
Notes Receivable [Abstract]        
Imputed interest rates on outstanding notes   4.00% 4.00% 4.00%
Retirement plan [Abstract]        
Percentage contribution by employer in relation to employee contribution to fund   100.00%    
Employer matching contribution   6.00%    
Vesting period under 401(k) plan   2 years    
Matching contribution by employer   $ 1,412 $ 1,195 $ 1,116
Other Liabilities [Abstract]        
Reduction in depreciation expense due to amortization of capitalize liability   $ 840 $ 1,047 $ 972
Foreign Currency [Abstract]        
Exchange rate | ر.س / $   3.75    
Income Tax Disclosure [Line Items]        
Federal corporate tax rate   35.00% 35.00% 35.00%
Plan [Member]        
Income Tax Disclosure [Line Items]        
Federal corporate tax rate 21.00%