Quarterly report pursuant to Section 13 or 15(d)

Entity Level Information - Additional Information (Details)

v3.19.2
Entity Level Information - Additional Information (Details)
$ in Thousands
6 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
Segment
Dec. 31, 2018
USD ($)
Revenues From External Customers And Long Lived Assets [Line Items]    
Number of reporting segment | Segment 1  
Allowance for credit losses $ 7 $ 11
Receivables | Customer Concentration | Customer One    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage 46.00% 44.00%
Receivables | Customer Concentration | Customer Two    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage 37.00% 43.00%
Receivables | Customer Concentration | Customer Three    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage 6.00%  
U.S [Member]    
Revenues From External Customers And Long Lived Assets [Line Items]    
Long-lived assets $ 1,397 $ 2,013
Asia Pacific [Member]    
Revenues From External Customers And Long Lived Assets [Line Items]    
Long-lived assets $ 510 $ 393