| Segment Information | 
Our segment information is as follows (in thousands): 
 |  
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
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 | 
 | 
 
   | 
   | 
Three months ended June 30,  | 
   | 
Six months ended June 30,  | 
 
   | 
   | 
2019  | 
   | 
2018  | 
   | 
2019  | 
   | 
2018  | 
 
Revenues:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Supply Chain Management Group  | 
   | 
$  | 
53,805  | 
 
  | 
   | 
$  | 
54,263  | 
 
  | 
   | 
$  | 
105,509  | 
 
  | 
   | 
$  | 
110,127  | 
 
  | 
 
Aviation Group  | 
   | 
54,997  | 
 
  | 
   | 
35,804  | 
 
  | 
   | 
104,367  | 
 
  | 
   | 
68,554  | 
 
  | 
 
Federal Services Group  | 
   | 
80,309  | 
 
  | 
   | 
80,327  | 
 
  | 
   | 
149,154  | 
 
  | 
   | 
168,610  | 
 
  | 
 
Total revenues  | 
   | 
$  | 
189,111  | 
 
  | 
   | 
$  | 
170,394  | 
 
  | 
   | 
$  | 
359,030  | 
 
  | 
   | 
$  | 
347,291  | 
 
  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Operating income:  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
 
Supply Chain Management Group  | 
   | 
$  | 
7,557  | 
 
  | 
   | 
$  | 
8,168  | 
 
  | 
   | 
$  | 
14,545  | 
 
  | 
   | 
$  | 
15,764  | 
 
  | 
 
Aviation Group  | 
   | 
5,204  | 
 
  | 
   | 
2,846  | 
 
  | 
   | 
8,252  | 
 
  | 
   | 
5,107  | 
 
  | 
 
Federal Services Group  | 
   | 
5,059  | 
 
  | 
   | 
3,606  | 
 
  | 
   | 
8,444  | 
 
  | 
   | 
6,084  | 
 
  | 
 
Corporate/unallocated expenses   | 
   | 
(1,404  | 
)  | 
   | 
(765  | 
)  | 
   | 
(3,012  | 
)  | 
   | 
(1,507  | 
)  | 
 
Operating income  | 
   | 
$  | 
16,416  | 
 
  | 
   | 
$  | 
13,855  | 
 
  | 
   | 
$  | 
28,229  | 
 
  | 
   | 
$  | 
25,448  | 
 
  | 
 
  
 
 | 
| Revenue by Customer | 
Our revenues by customer is as follows (dollars in thousands): 
 |  
 | 
 | 
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 | 
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 | 
 | 
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   | 
   | 
Three months ended June 30,  | 
   | 
Six months ended June 30,  | 
 
Customer  | 
   | 
2019  | 
   | 
%  | 
   | 
2018  | 
   | 
%  | 
   | 
2019  | 
   | 
%  | 
   | 
2018  | 
   | 
%  | 
 
USPS  | 
   | 
$  | 
42,112  | 
 
  | 
   | 
22.3  | 
%  | 
   | 
$  | 
43,089  | 
 
  | 
   | 
25.3  | 
%  | 
   | 
$  | 
84,795  | 
 
  | 
   | 
23.6  | 
%  | 
   | 
$  | 
87,120  | 
 
  | 
   | 
25.1  | 
%  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
U.S. Navy  | 
   | 
22,202  | 
 
  | 
   | 
11.8  | 
%  | 
   | 
35,696  | 
 
  | 
   | 
20.9  | 
%  | 
   | 
42,807  | 
 
  | 
   | 
11.9  | 
%  | 
   | 
78,281  | 
 
  | 
   | 
22.5  | 
%  | 
 
U.S. Army  | 
   | 
47,333  | 
 
  | 
   | 
25.0  | 
%  | 
   | 
41,548  | 
 
  | 
   | 
24.4  | 
%  | 
   | 
84,052  | 
 
  | 
   | 
23.4  | 
%  | 
   | 
84,335  | 
 
  | 
   | 
24.3  | 
%  | 
 
U.S. Air Force  | 
   | 
5,545  | 
 
  | 
   | 
2.9  | 
%  | 
   | 
4,943  | 
 
  | 
   | 
2.9  | 
%  | 
   | 
10,922  | 
 
  | 
   | 
3.1  | 
%  | 
   | 
7,224  | 
 
  | 
   | 
2.1  | 
%  | 
 
Total - DoD  | 
   | 
75,080  | 
 
  | 
   | 
39.7  | 
%  | 
   | 
82,187  | 
 
  | 
   | 
48.2  | 
%  | 
   | 
137,781  | 
 
  | 
   | 
38.4  | 
%  | 
   | 
169,840  | 
 
  | 
   | 
48.9  | 
%  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Commercial aviation  | 
   | 
54,086  | 
 
  | 
   | 
28.6  | 
%  | 
   | 
34,037  | 
 
  | 
   | 
20.0  | 
%  | 
   | 
102,561  | 
 
  | 
   | 
28.6  | 
%  | 
   | 
65,572  | 
 
  | 
   | 
18.9  | 
%  | 
 
Other commercial  | 
   | 
5,090  | 
 
  | 
   | 
2.7  | 
%  | 
   | 
3,444  | 
 
  | 
   | 
2.0  | 
%  | 
   | 
10,174  | 
 
  | 
   | 
2.8  | 
%  | 
   | 
7,032  | 
 
  | 
   | 
2.0  | 
%  | 
 
Total - Commercial  | 
   | 
59,176  | 
 
  | 
   | 
31.3  | 
%  | 
   | 
37,481  | 
 
  | 
   | 
22.0  | 
%  | 
   | 
112,735  | 
 
  | 
   | 
31.4  | 
%  | 
   | 
72,604  | 
 
  | 
   | 
20.9  | 
%  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Other government  | 
   | 
12,743  | 
 
  | 
   | 
6.7  | 
%  | 
   | 
7,637  | 
 
  | 
   | 
4.5  | 
%  | 
   | 
23,719  | 
 
  | 
   | 
6.6  | 
%  | 
   | 
17,727  | 
 
  | 
   | 
5.1  | 
%  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Total  | 
   | 
$  | 
189,111  | 
 
  | 
   | 
100  | 
%  | 
   | 
$  | 
170,394  | 
 
  | 
   | 
100  | 
%  | 
   | 
$  | 
359,030  | 
 
  | 
   | 
100  | 
%  | 
   | 
$  | 
347,291  | 
 
  | 
   | 
100  | 
%  | 
 
  
 
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