Annual report pursuant to Section 13 and 15(d)

Concentration of Risk, Segment and Geographic Information - Additional Information 2 (Details)

v3.8.0.1
Concentration of Risk, Segment and Geographic Information - Additional Information 2 (Details)
12 Months Ended
Dec. 31, 2017
Segment
Concentration Of Risk Segment And Geographic Information [Abstract]  
Number of operating segments 1