Quarterly report pursuant to Section 13 or 15(d)

Revenue - Narrative (Details)

v3.10.0.1
Revenue - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Jan. 01, 2018
Dec. 31, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Unbilled receivables, net $ 37,955   $ 37,955   $ 47,559 $ 42,577
Contract with customer, liability 3,900   3,900   $ 9,800  
Contract with Customer, Liability, Revenue Recognized $ 1,200   $ 7,700      
Concentration risk, percentage 100.00% 100.00% 100.00% 100.00%    
Revenue, remaining performance obligation $ 339,000   $ 339,000      
Sales Revenue, Net | Product Concentration Risk | Transferred over Time            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Concentration risk, percentage 57.00%   57.00%      
Sales Revenue, Net | Product Concentration Risk | Transferred at Point in Time            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Concentration risk, percentage 43.00%   43.00%