Quarterly report pursuant to Section 13 or 15(d)

Entity Level Information - Percentage of Total Revenues (Details)

v3.19.2
Entity Level Information - Percentage of Total Revenues (Details) - Revenues - Customer Concentration
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Customer A    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage 37.00%  
Customer B    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage 14.00% 38.00%
Customer C    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage 13.00% 6.00%
Customer D    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage   17.00%
Customer E    
Revenues From External Customers And Long Lived Assets [Line Items]    
Concentration risk percentage   10.00%