Quarterly report pursuant to Section 13 or 15(d)

Business Segments and Customer Information - Major Customers (Details)

v3.19.3
Business Segments and Customer Information - Major Customers (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Revenue, Major Customer [Line Items]        
Revenues $ 198,326 $ 168,931 $ 557,356 $ 516,222
USPS        
Revenue, Major Customer [Line Items]        
Revenues 42,282 43,031 127,077 130,151
U.S. Navy        
Revenue, Major Customer [Line Items]        
Revenues 30,123 37,013 72,930 115,294
U.S. Army        
Revenue, Major Customer [Line Items]        
Revenues 48,529 38,167 132,581 122,502
U.S. Air Force        
Revenue, Major Customer [Line Items]        
Revenues 6,401 4,822 17,323 12,046
Total - DoD        
Revenue, Major Customer [Line Items]        
Revenues 85,053 80,002 222,834 249,842
Commercial aviation        
Revenue, Major Customer [Line Items]        
Revenues 56,839 32,641 159,400 98,213
Other commercial        
Revenue, Major Customer [Line Items]        
Revenues 6,015 3,386 16,189 10,418
Total - Commercial        
Revenue, Major Customer [Line Items]        
Revenues 62,854 36,027 175,589 108,631
Other government        
Revenue, Major Customer [Line Items]        
Revenues $ 8,137 $ 9,871 $ 31,856 $ 27,598
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 | USPS        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 21.30% 25.50% 22.80% 25.20%
Customer Concentration Risk | Sales Revenue, Net | U.S. Navy        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 15.20% 21.90% 13.10% 22.40%
Customer Concentration Risk | Sales Revenue, Net | U.S. Army        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 24.50% 22.60% 23.80% 23.70%
Customer Concentration Risk | Sales Revenue, Net | U.S. Air Force        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 3.20% 2.90% 3.10% 2.30%
Customer Concentration Risk | Sales Revenue, Net | Total - DoD        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 42.90% 47.40% 40.00% 48.40%
Customer Concentration Risk | Sales Revenue, Net | Commercial aviation        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 28.70% 19.30% 28.60% 19.00%
Customer Concentration Risk | Sales Revenue, Net | Other commercial        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 3.00% 2.00% 2.90% 2.00%
Customer Concentration Risk | Sales Revenue, Net | Total - Commercial        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 31.70% 21.30% 31.50% 21.00%
Customer Concentration Risk | Sales Revenue, Net | Other government        
Revenue, Major Customer [Line Items]        
Percentage of revenue by customer 4.10% 5.80% 5.70% 5.40%