Quarterly report pursuant to Section 13 or 15(d)

Business Segments and Customer Information - Major Customers (Details)

v3.10.0.1
Business Segments and Customer Information - Major Customers (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Revenue, Major Customer [Line Items]        
Revenues $ 170,394 $ 193,860 $ 347,291 $ 391,154
Percentage of revenue by customer 100.00% 100.00% 100.00% 100.00%
U.S. Postal Service        
Revenue, Major Customer [Line Items]        
Revenues $ 43,089 $ 45,959 $ 87,120 $ 92,428
Percentage of revenue by customer 25.30% 23.70% 25.10% 23.60%
U.S. Navy        
Revenue, Major Customer [Line Items]        
Revenues $ 35,696 $ 52,030 $ 78,281 $ 104,526
Percentage of revenue by customer 20.90% 26.80% 22.50% 26.70%
U.S. Army        
Revenue, Major Customer [Line Items]        
Revenues $ 41,548 $ 50,399 $ 84,335 $ 104,500
Percentage of revenue by customer 24.40% 26.10% 24.30% 26.70%
U.S. Air Force        
Revenue, Major Customer [Line Items]        
Revenues $ 4,943 $ 1,822 $ 7,224 $ 2,840
Percentage of revenue by customer 2.90% 0.90% 2.10% 0.70%
Total - DoD        
Revenue, Major Customer [Line Items]        
Revenues $ 82,187 $ 104,251 $ 169,840 $ 211,866
Percentage of revenue by customer 48.20% 53.80% 48.90% 54.10%
Commercial aviation        
Revenue, Major Customer [Line Items]        
Revenues $ 34,037 $ 32,265 $ 65,572 $ 64,069
Percentage of revenue by customer 20.00% 16.60% 18.90% 16.40%
Other commercial        
Revenue, Major Customer [Line Items]        
Revenues $ 3,444 $ 3,308 $ 7,032 $ 6,437
Percentage of revenue by customer 2.00% 1.70% 2.00% 1.70%
Total - Commercial        
Revenue, Major Customer [Line Items]        
Revenues $ 37,481 $ 35,573 $ 72,604 $ 70,506
Percentage of revenue by customer 22.00% 18.30% 20.90% 18.10%
Other government        
Revenue, Major Customer [Line Items]        
Revenues $ 7,637 $ 8,077 $ 17,727 $ 16,354
Percentage of revenue by customer 4.50% 4.20% 5.10% 4.20%