Quarterly report pursuant to Section 13 or 15(d)

Business Segments and Customer Information - Major Customers (Details)

v3.21.1
Business Segments and Customer Information - Major Customers (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Revenue, Major Customer [Line Items]    
Revenues $ 164,981 $ 177,418
DoD    
Revenue, Major Customer [Line Items]    
Revenues 45,888 64,134
Other government    
Revenue, Major Customer [Line Items]    
Revenues 59,992 45,990
Commercial    
Revenue, Major Customer [Line Items]    
Revenues $ 59,101 $ 67,294
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 28.00% 36.00%
Customer Concentration Risk | Sales Revenue, Net | Other government    
Revenue, Major Customer [Line Items]    
Percentage of revenue by customer 36.00% 26.00%
Customer Concentration Risk | Sales Revenue, Net | Commercial    
Revenue, Major Customer [Line Items]    
Percentage of revenue by customer 36.00% 38.00%