Quarterly report pursuant to Section 13 or 15(d)

Business Segments and Customer Information - Major Customers (Details)

v3.20.2
Business Segments and Customer Information - Major Customers (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Revenue, Major Customer [Line Items]        
Revenues $ 168,715 $ 189,111 $ 346,133 $ 359,030
DoD        
Revenue, Major Customer [Line Items]        
Revenues 64,887 75,080 129,021 137,781
Other government        
Revenue, Major Customer [Line Items]        
Revenues 63,666 54,855 109,656 108,514
Commercial        
Revenue, Major Customer [Line Items]        
Revenues $ 40,162 $ 59,176 $ 107,456 $ 112,735
Customer Concentration Risk | Sales Revenue, Net        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 100.00% 100.00% 100.00% 100.00%
Customer Concentration Risk | Sales Revenue, Net | DoD        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 38.00% 40.00% 37.00% 38.00%
Customer Concentration Risk | Sales Revenue, Net | Other government        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 38.00% 29.00% 32.00% 31.00%
Customer Concentration Risk | Sales Revenue, Net | Commercial        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 24.00% 31.00% 31.00% 31.00%