Quarterly report pursuant to Section 13 or 15(d)

Revenue - Additional Information (Details)

v3.19.2
Revenue - Additional Information (Details)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
Mar. 31, 2019
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2019
business_line
Jun. 30, 2018
USD ($)
Revenue from Contract with Customer [Abstract]          
Number of business lines | business_line       2  
Disaggregation of Revenue [Line Items]          
Revenues $ 156,031 $ 157,397 $ 118,603   $ 228,278
Typical payment term (days)       30 days  
Lease revenue          
Disaggregation of Revenue [Line Items]          
Revenues 42,431 42,041      
Service revenue          
Disaggregation of Revenue [Line Items]          
Revenues 113,600 115,356      
Reimbursable revenue          
Disaggregation of Revenue [Line Items]          
Revenues $ 18,465 $ 28,541     $ 27,036
Minimum          
Disaggregation of Revenue [Line Items]          
Revenue, remaining performance obligation, expected timing of satisfaction, period       2 months  
Maximum          
Disaggregation of Revenue [Line Items]          
Revenue, remaining performance obligation, expected timing of satisfaction, period       60 months