Quarterly report pursuant to Section 13 or 15(d)

Business Segments and Customer Information - Major Customers (Details)

v3.20.1
Business Segments and Customer Information - Major Customers (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Revenue, Major Customer [Line Items]    
Revenues $ 177,418 $ 169,919
DoD    
Revenue, Major Customer [Line Items]    
Revenues 64,134 62,701
Other government    
Revenue, Major Customer [Line Items]    
Revenues 45,990 53,659
Commercial    
Revenue, Major Customer [Line Items]    
Revenues $ 67,294 $ 53,559
Customer Concentration Risk | Sales Revenue, Net    
Revenue, Major Customer [Line Items]    
Percentage of revenue by customer 100.00% 100.00%
Customer Concentration Risk | Sales Revenue, Net | DoD    
Revenue, Major Customer [Line Items]    
Percentage of revenue by customer 36.00% 37.00%
Customer Concentration Risk | Sales Revenue, Net | Other government    
Revenue, Major Customer [Line Items]    
Percentage of revenue by customer 26.00% 32.00%
Customer Concentration Risk | Sales Revenue, Net | Commercial    
Revenue, Major Customer [Line Items]    
Percentage of revenue by customer 38.00% 31.00%