Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies (Details)

v3.19.1
Commitments and Contingencies (Details)
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Revenue | Customer concentration    
Certain Risks and Concentrations    
Concentration Risk, Percentage 73.00% 72.00%