Annual report pursuant to Section 13 and 15(d)

Business Segments and Customer Information (Details)

v3.8.0.1
Business Segments and Customer Information (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Segment Reporting Information [Line Items]                      
Revenues                 $ 760,113 $ 691,790 $ 533,982
Operating income $ 12,887 $ 12,237 $ 15,005 $ 14,196 $ 13,286 $ 13,623 $ 11,879 $ 12,741 54,325 51,529 50,539
Total assets 629,013       661,839       629,013 661,839  
Operating Segments                      
Segment Reporting Information [Line Items]                      
Revenues                 760,113 691,790 533,982
Operating income                 54,325 51,529 50,539
Depreciation and amortization                 25,882 26,046 25,541
Capital expenditures                 3,313 7,372 10,562
Total assets 629,013       661,839       629,013 661,839  
Operating Segments | Supply Chain Management                      
Segment Reporting Information [Line Items]                      
Revenues                 214,542 205,475 196,772
Operating income                 33,754 34,632 35,453
Depreciation and amortization                 6,536 6,445 7,074
Capital expenditures                 1,376 4,195 7,544
Total assets 176,860       185,004       176,860 185,004  
Operating Segments | Aviation                      
Segment Reporting Information [Line Items]                      
Revenues                 134,809 133,466 119,729
Operating income                 9,695 12,823 10,635
Depreciation and amortization                 4,835 5,461 5,865
Capital expenditures                 1,387 1,459 959
Total assets 282,738       291,500       282,738 291,500  
Operating Segments | Federal Services Group                      
Segment Reporting Information [Line Items]                      
Revenues                 410,762 352,849 217,481
Operating income                 13,419 7,796 6,802
Depreciation and amortization                 14,511 14,140 12,602
Capital expenditures                 177 94 94
Total assets 102,372       107,549       102,372 107,549  
Operating Segments | Corporate                      
Segment Reporting Information [Line Items]                      
Total assets $ 67,043       $ 77,786       67,043 77,786  
Corporate expenses                      
Segment Reporting Information [Line Items]                      
Operating income                 (2,543) (3,722) (2,351)
Capital expenditures                 $ 373 $ 1,624 $ 1,965