Quarterly report pursuant to Section 13 or 15(d)

Segment Information Concentrations (Details)

v3.19.1
Segment Information Concentrations (Details)
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2018
Concentration Risk [Line Items]    
Concentration Risk, Percentage 10.00% 11.60%