XML 61 R47.htm IDEA: XBRL DOCUMENT v3.19.1
Summary of Significant Accounting Policies - Segment Information - Additional Information (Details)
$ in Thousands
3 Months Ended
Mar. 31, 2019
USD ($)
segment
Mar. 31, 2018
USD ($)
Dec. 31, 2018
USD ($)
Segment Reporting Information [Line Items]      
Number of segments | segment 1    
Property, plant and equipment, net $ 136,357   $ 128,874
Foreign Countries      
Segment Reporting Information [Line Items]      
Property, plant and equipment, net 17,377   $ 16,839
Revenues $ 2,265 $ 4,203