| Segment Information | 
Our segment information is as follows (in thousands): 
  
For the years ended December 31,  | 
  | 
 | 
  | 
  | 
 | 
  | 
  | 
 | 
  | 
 
|   | 
  | 
2015  | 
  | 
  | 
2014  | 
  | 
  | 
2013  | 
  | 
 
Revenues  | 
  | 
 | 
  | 
  | 
 | 
  | 
  | 
 | 
  | 
 
  Supply Chain Management Group  | 
  | 
$  | 
196,772  | 
  | 
  | 
$  | 
172,482  | 
  | 
  | 
$  | 
154,702  | 
  | 
 
  Aviation Group  | 
  | 
  | 
119,729  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
 
  Federal Services Group  | 
  | 
  | 
166,973  | 
  | 
  | 
  | 
190,761  | 
  | 
  | 
  | 
242,343  | 
  | 
 
  IT, Energy and Management Consulting Group  | 
  | 
  | 
50,508  | 
  | 
  | 
  | 
60,828  | 
  | 
  | 
  | 
74,593  | 
  | 
 
    Total revenues  | 
  | 
$  | 
533,982  | 
  | 
  | 
$  | 
424,071  | 
  | 
  | 
$  | 
471,638  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
Operating income:  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
  Supply Chain Management Group  | 
  | 
$  | 
35,453  | 
  | 
  | 
$  | 
29,694  | 
  | 
  | 
$  | 
27,299  | 
  | 
 
  Aviation Group  | 
  | 
  | 
10,635  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
 
  Federal Services Group  | 
  | 
  | 
2,071  | 
  | 
  | 
  | 
3,452  | 
  | 
  | 
  | 
9,469  | 
  | 
 
  IT, Energy and Management Consulting Group  | 
  | 
  | 
4,731  | 
  | 
  | 
  | 
6,634  | 
  | 
  | 
  | 
9,061  | 
  | 
 
  Corporate  | 
  | 
  | 
(2,351  | 
)  | 
  | 
  | 
(2,850  | 
)  | 
  | 
  | 
(1,726  | 
)  | 
 
    Operating income  | 
  | 
$  | 
50,539  | 
  | 
  | 
$  | 
36,930  | 
  | 
  | 
$  | 
44,103  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
Depreciation and amortization expense:  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
  Supply Chain Management Group  | 
  | 
$  | 
7,074  | 
  | 
  | 
$  | 
5,373  | 
  | 
  | 
$  | 
4,265  | 
  | 
 
  Aviation Group  | 
  | 
  | 
5,865  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
 
  Federal Services Group  | 
  | 
  | 
10,635  | 
  | 
  | 
  | 
11,320  | 
  | 
  | 
  | 
13,356  | 
  | 
 
  IT, Energy and Management Consulting Group  | 
  | 
  | 
1,967  | 
  | 
  | 
  | 
2,077  | 
  | 
  | 
  | 
2,387  | 
  | 
 
    Total depreciation and amortization  | 
  | 
$  | 
25,541  | 
  | 
  | 
$  | 
18,770  | 
  | 
  | 
$  | 
20,008  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
Capital expenditures:  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
  Supply Chain Management Group  | 
  | 
$  | 
7,544  | 
  | 
  | 
$  | 
2,524  | 
  | 
  | 
$  | 
895  | 
  | 
 
  Aviation Group  | 
  | 
  | 
959  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
 
  Federal Services Group  | 
  | 
  | 
78  | 
  | 
  | 
  | 
230  | 
  | 
  | 
  | 
1,447  | 
  | 
 
  IT, Energy and Management Consulting Group  | 
  | 
  | 
16  | 
  | 
  | 
  | 
199  | 
  | 
  | 
  | 
71  | 
  | 
 
  Corporate  | 
  | 
  | 
1,965  | 
  | 
  | 
  | 
461  | 
  | 
  | 
  | 
2,003  | 
  | 
 
    Total capital expenditures  | 
  | 
$  | 
10,562  | 
  | 
  | 
$  | 
3,414  | 
  | 
  | 
$  | 
4,416  | 
  | 
 
 
  
|   | 
  | 
December 31,  | 
  | 
 
|   | 
  | 
2015  | 
  | 
  | 
2014  | 
  | 
 
Total assets:  | 
  | 
 | 
  | 
  | 
 | 
  | 
 
  Supply Chain Management Group  | 
  | 
$  | 
189,654  | 
  | 
  | 
$  | 
192,720  | 
  | 
 
  Aviation Group  | 
  | 
  | 
264,160  | 
  | 
  | 
  | 
-  | 
  | 
 
  Federal Services Group  | 
  | 
  | 
38,626  | 
  | 
  | 
  | 
36,225  | 
  | 
 
  IT, Energy and Management Consulting Group  | 
  | 
  | 
47,107  | 
  | 
  | 
  | 
49,790  | 
  | 
 
  Corporate  | 
  | 
  | 
82,587  | 
  | 
  | 
  | 
76,595  | 
  | 
 
    Total assets  | 
  | 
$  | 
622,134  | 
  | 
  | 
$  | 
355,330  | 
  | 
 
 
 
 | 
| Revenue by Customer | 
Our customers also include various other government agencies and commercial entities. Our revenue by customer is as follows for the years ended December 31, (in thousands): 
  
|   | 
  | 
Revenues by Customer  | 
  | 
 
|   | 
  | 
(dollars in thousands)  | 
  | 
 
|   | 
  | 
Years ended December 31,  | 
  | 
 
Customer  | 
  | 
2015  | 
  | 
  | 
%  | 
  | 
  | 
2014  | 
  | 
  | 
%  | 
  | 
  | 
2013  | 
  | 
  | 
%  | 
  | 
 
U. S. Postal Service  | 
  | 
$  | 
184,876  | 
  | 
  | 
  | 
34.6  | 
  | 
  | 
$  | 
167,268  | 
  | 
  | 
  | 
39.4  | 
  | 
  | 
$  | 
142,203  | 
  | 
  | 
  | 
30.1  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
U.S. Army  | 
  | 
  | 
80,086  | 
  | 
  | 
  | 
15.0  | 
  | 
  | 
  | 
101,714  | 
  | 
  | 
  | 
24.0  | 
  | 
  | 
  | 
101,736  | 
  | 
  | 
  | 
21.6  | 
  | 
 
U.S. Navy  | 
  | 
  | 
98,887  | 
  | 
  | 
  | 
18.5  | 
  | 
  | 
  | 
88,007  | 
  | 
  | 
  | 
20.7  | 
  | 
  | 
  | 
123,307  | 
  | 
  | 
  | 
26.1  | 
  | 
 
U.S. Air Force  | 
  | 
  | 
3,558  | 
  | 
  | 
  | 
0.7  | 
  | 
  | 
  | 
3,323  | 
  | 
  | 
  | 
0.8  | 
  | 
  | 
  | 
3,625  | 
  | 
  | 
  | 
0.8  | 
  | 
 
Total - DoD  | 
  | 
  | 
182,531  | 
  | 
  | 
  | 
34.2  | 
  | 
  | 
  | 
193,044  | 
  | 
  | 
  | 
45.5  | 
  | 
  | 
  | 
228,668  | 
  | 
  | 
  | 
48.5  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
Commercial Aviation  | 
  | 
  | 
119,729  | 
  | 
  | 
  | 
22.4  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
  | 
  | 
-  | 
  | 
 
Other Commercial  | 
  | 
  | 
4,653  | 
  | 
  | 
  | 
0.9  | 
  | 
  | 
  | 
3,680  | 
  | 
  | 
  | 
0.9  | 
  | 
  | 
  | 
2,250  | 
  | 
  | 
  | 
0.5  | 
  | 
 
Total - Commercial  | 
  | 
  | 
124,382  | 
  | 
  | 
  | 
23.3  | 
  | 
  | 
  | 
3,680  | 
  | 
  | 
  | 
0.9  | 
  | 
  | 
  | 
2,250  | 
  | 
  | 
  | 
0.5  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
Department of Energy  | 
  | 
  | 
16,020  | 
  | 
  | 
  | 
3.0  | 
  | 
  | 
  | 
19,000  | 
  | 
  | 
  | 
4.5  | 
  | 
  | 
  | 
20,124  | 
  | 
  | 
  | 
4.3  | 
  | 
 
Social Security Administration  | 
  | 
  | 
9,666  | 
  | 
  | 
  | 
1.8  | 
  | 
  | 
  | 
10,153  | 
  | 
  | 
  | 
2.4  | 
  | 
  | 
  | 
12,981  | 
  | 
  | 
  | 
2.8  | 
  | 
 
Department of Treasury  | 
  | 
  | 
1,405  | 
  | 
  | 
  | 
0.3  | 
  | 
  | 
  | 
10,897  | 
  | 
  | 
  | 
2.6  | 
  | 
  | 
  | 
35,929  | 
  | 
  | 
  | 
7.6  | 
  | 
 
Other Government  | 
  | 
  | 
15,102  | 
  | 
  | 
  | 
2.8  | 
  | 
  | 
  | 
20,029  | 
  | 
  | 
  | 
4.7  | 
  | 
  | 
  | 
29,483  | 
  | 
  | 
  | 
6.2  | 
  | 
 
Total - Other Civilian Agencies  | 
  | 
  | 
42,193  | 
  | 
  | 
  | 
7.9  | 
  | 
  | 
  | 
60,079  | 
  | 
  | 
  | 
14.2  | 
  | 
  | 
  | 
98,517  | 
  | 
  | 
  | 
20.9  | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
Total  | 
  | 
$  | 
533,982  | 
  | 
  | 
  | 
100.0  | 
  | 
  | 
$  | 
424,071  | 
  | 
  | 
  | 
100.0  | 
  | 
  | 
$  | 
471,638  | 
  | 
  | 
  | 
100.0  | 
  | 
 
 
 
 |