Quarterly report pursuant to Section 13 or 15(d)

Revenue from Contracts with Customers - Narrative (Details)

v3.10.0.1
Revenue from Contracts with Customers - Narrative (Details)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2018
USD ($)
Sep. 30, 2017
USD ($)
Sep. 30, 2018
USD ($)
business_line
Sep. 30, 2017
USD ($)
Dec. 31, 2017
USD ($)
Revenue from Contract with Customer [Abstract]          
Number of business lines | business_line     2    
Disaggregation of Revenue [Line Items]          
Typical payment term     30 days    
Revenues $ 123,395 $ 118,308 $ 351,673 $ 326,186  
Capitalized mobilization costs 6,400   6,400   $ 3,100
Capitalized contract cost, amortization 1,800   3,900    
Reimbursable revenue          
Disaggregation of Revenue [Line Items]          
Revenues $ 13,400 $ 15,000 $ 40,400 $ 45,500  
Minimum          
Disaggregation of Revenue [Line Items]          
Revenue, remaining performance obligation, expected timing of satisfaction, period     2    
Maximum          
Disaggregation of Revenue [Line Items]          
Revenue, remaining performance obligation, expected timing of satisfaction, period     60