Business Segments and Customer Information (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | $ 195,271 | $ 198,326 | $ 189,111 | $ 169,919 | $ 180,996 | $ 168,931 | $ 170,394 | $ 176,897 | $ 752,627 | $ 697,218 | $ 760,113 |
| Operating income | 14,813 | $ 17,215 | $ 16,416 | $ 11,813 | 13,085 | $ 15,697 | $ 13,855 | $ 11,593 | 60,257 | 54,230 | 54,325 |
| Total assets | 845,864 | 638,828 | 845,864 | 638,828 | |||||||
| Supply Chain Management | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 214,520 | 214,809 | |||||||||
| Aviation | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 224,546 | 145,423 | |||||||||
| Federal Services Group | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 313,561 | 336,986 | |||||||||
| Operating Segments | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 752,627 | 697,218 | 760,113 | ||||||||
| Operating income | 60,257 | 54,230 | 54,325 | ||||||||
| Depreciation and amortization | 26,927 | 25,224 | 25,882 | ||||||||
| Capital expenditures | 9,660 | 3,117 | 3,313 | ||||||||
| Total assets | 845,864 | 638,828 | 845,864 | 638,828 | |||||||
| Operating Segments | Supply Chain Management | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 214,520 | 214,809 | 214,542 | ||||||||
| Operating income | 29,819 | 30,626 | 33,754 | ||||||||
| Depreciation and amortization | 11,085 | 7,299 | 6,536 | ||||||||
| Capital expenditures | 1,076 | 802 | 1,376 | ||||||||
| Total assets | 170,142 | 166,015 | 170,142 | 166,015 | |||||||
| Operating Segments | Aviation | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 224,546 | 145,423 | 134,809 | ||||||||
| Operating income | 17,901 | 11,076 | 9,695 | ||||||||
| Depreciation and amortization | 12,546 | 5,123 | 4,835 | ||||||||
| Capital expenditures | 8,396 | 1,772 | 1,387 | ||||||||
| Total assets | 522,446 | 316,197 | 522,446 | 316,197 | |||||||
| Operating Segments | Federal Services Group | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenues | 313,561 | 336,986 | 410,762 | ||||||||
| Operating income | 18,144 | 15,797 | 13,419 | ||||||||
| Depreciation and amortization | 3,296 | 12,802 | 14,511 | ||||||||
| Capital expenditures | 58 | 209 | 177 | ||||||||
| Total assets | 88,966 | 92,098 | 88,966 | 92,098 | |||||||
| Operating Segments | Corporate | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Total assets | $ 64,310 | $ 64,518 | 64,310 | 64,518 | |||||||
| Corporate, Non-Segment | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Operating income | (5,607) | (3,269) | (2,543) | ||||||||
| Capital expenditures | $ 130 | $ 334 | $ 373 | ||||||||