| Segment Reporting [Table Text Block] |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Three Months Ended September 30, 2026 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 70,555 | | | $ | 95,405 | | | $ | 121,635 | | | $ | 26,738 | | | $ | 314,333 | |
| Fuel surcharge revenue(1) | | | 18,918 | | | | 19,719 | | | | - | | | | 207 | | | | 38,844 | |
| Subtotal operating revenues | | $ | 89,473 | | | $ | 115,124 | | | $ | 121,635 | | | $ | 26,945 | | | $ | 353,177 | |
| Other revenues | | | | | | | | | | | | | | | | | | | 717 | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 353,894 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 26,960 | | | | 45,794 | | | | 4,301 | | | | 13,669 | | | | | |
| Fuel expense(1) | | | 17,537 | | | | 20,866 | | | | - | | | | 267 | | | | | |
| Operations and maintenance | | | 8,747 | | | | 12,295 | | | | 966 | | | | 1,904 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 13,482 | | | | 7,149 | | | | 104,284 | | | | 1,240 | | | | | |
| Operating taxes and licenses | | | 220 | | | | 743 | | | | 33 | | | | 426 | | | | | |
| Insurance and claims | | | 5,540 | | | | 5,679 | | | | 634 | | | | 239 | | | | | |
| Communications and utilities | | | 1 | | | | 220 | | | | 23 | | | | 301 | | | | | |
| General supplies and expenses | | | 510 | | | | 441 | | | | 1,191 | | | | 3,840 | | | | | |
| Depreciation and amortization | | | - | | | | 5,311 | | | | 102 | | | | 437 | | | | | |
| Gain on disposition of property and equipment, net | | | - | | | | (97 | ) | | | - | | | | - | | | | | |
| Total allocated overhead | | | 8,630 | | | | 10,307 | | | | 2,734 | | | | 2,925 | | | | | |
| Segment operating expenses | | | 81,627 | | | | 108,708 | | | | 114,268 | | | | 25,248 | | | | 329,851 | |
| Subtotal operating income | | $ | 7,846 | | | $ | 6,416 | | | $ | 7,367 | | | $ | 1,697 | | | $ | 24,043 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (11,549 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 12,494 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (3,854 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 5,650 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 14,290 | |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Three Months Ended September 30, 2025 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 80,184 | | | $ | 91,581 | | | $ | 72,220 | | | $ | 24,802 | | | $ | 268,787 | |
| Fuel surcharge revenue(1) | | | 14,448 | | | | 13,439 | | | | - | | | | 162 | | | | 28,049 | |
| Subtotal operating revenues | | $ | 94,632 | | | $ | 105,020 | | | $ | 72,220 | | | $ | 24,964 | | | $ | 296,836 | |
| Other revenues | | | | | | | | | | | | | | | | | | | 53 | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 296,889 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 30,756 | | | | 43,760 | | | | 2,758 | | | | 12,044 | | | | | |
| Fuel expense(1) | | | 14,584 | | | | 14,690 | | | | - | | | | 167 | | | | | |
| Operations and maintenance | | | 10,099 | | | | 12,667 | | | | 689 | | | | 1,471 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 17,742 | | | | 8,453 | | | | 62,545 | | | | 1,052 | | | | | |
| Operating taxes and licenses | | | 356 | | | | 667 | | | | 18 | | | | 383 | | | | | |
| Insurance and claims | | | 6,647 | | | | 5,057 | | | | 205 | | | | 220 | | | | | |
| Communications and utilities | | | - | | | | 196 | | | | 7 | | | | 249 | | | | | |
| General supplies and expenses | | | 235 | | | | 482 | | | | 769 | | | | 4,161 | | | | | |
| Depreciation and amortization | | | 1 | | | | 4,369 | | | | 22 | | | | 461 | | | | | |
| Gain on disposition of property and equipment, net | | | - | | | | (63 | ) | | | - | | | | - | | | | | |
| Total allocated overhead | | | 9,133 | | | | 10,643 | | | | 2,247 | | | | 2,258 | | | | | |
| Segment operating expenses | | | 89,553 | | | | 100,921 | | | | 69,260 | | | | 22,466 | | | | 282,200 | |
| Segment operating income | | $ | 5,079 | | | $ | 4,099 | | | $ | 2,960 | | | $ | 2,498 | | | $ | 14,689 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (6,763 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 7,926 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (3,468 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 3,578 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 8,036 | |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Nine Months Ended September 30, 2026 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 216,246 | | | $ | 280,489 | | | $ | 311,908 | | | $ | 81,012 | | | $ | 889,655 | |
| Fuel surcharge revenue(1) | | | 51,318 | | | | 50,424 | | | | - | | | | 518 | | | | 102,260 | |
| Subtotal operating revenues | | $ | 267,564 | | | $ | 330,913 | | | $ | 311,908 | | | $ | 81,530 | | | $ | 991,915 | |
| Other revenues | | | | | | | | | | | | | | | | | | | 2,013 | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 993,928 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 82,616 | | | | 134,786 | | | | 11,404 | | | | 42,231 | | | | | |
| Fuel expense(1) | | | 50,235 | | | | 54,122 | | | | - | | | | 730 | | | | | |
| Operations and maintenance | | | 26,972 | | | | 35,106 | | | | 2,232 | | | | 5,585 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 43,389 | | | | 21,303 | | | | 272,456 | | | | 3,546 | | | | | |
| Operating taxes and licenses | | | 781 | | | | 2,205 | | | | 78 | | | | 1,295 | | | | | |
| Insurance and claims | | | 18,503 | | | | 16,878 | | | | 1,808 | | | | 728 | | | | | |
| Communications and utilities | | | 2 | | | | 668 | | | | 92 | | | | 972 | | | | | |
| General supplies and expenses | | | 1,317 | | | | 1,235 | | | | 3,585 | | | | 11,850 | | | | | |
| Depreciation and amortization | | | 1 | | | | 15,110 | | | | 304 | | | | 1,285 | | | | | |
| Gain on disposition of property and equipment, net | | | - | | | | (84 | ) | | | - | | | | - | | | | | |
| Total allocated overhead | | | 24,695 | | | | 29,803 | | | | 7,140 | | | | 8,259 | | | | | |
| Segment operating expenses | | | 248,511 | | | | 311,132 | | | | 299,099 | | | | 76,481 | | | | 935,223 | |
| Segment operating income | | $ | 19,053 | | | $ | 19,781 | | | $ | 12,809 | | | $ | 5,049 | | | $ | 58,705 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (31,088 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 27,617 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (10,721 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 14,602 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 31,498 | |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Nine Months Ended September 30, 2025 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 243,662 | | | $ | 263,827 | | | $ | 206,620 | | | $ | 74,429 | | | $ | 788,538 | |
| Fuel surcharge revenue(1) | | | 42,963 | | | | 37,079 | | | | - | | | | 465 | | | | 80,507 | |
| Subtotal operating revenues | | $ | 286,625 | | | $ | 300,906 | | | $ | 206,620 | | | $ | 74,894 | | | $ | 869,045 | |
| Other revenues | | | | | | | | | | | | | | | | | | | 53 | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 869,098 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 94,398 | | | | 125,160 | | | | 7,880 | | | | 35,822 | | | | | |
| Fuel expense(1) | | | 43,854 | | | | 41,328 | | | | - | | | | 498 | | | | | |
| Operations and maintenance | | | 31,263 | | | | 34,581 | | | | 1,195 | | | | 4,154 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 51,439 | | | | 26,027 | | | | 176,734 | | | | 3,302 | | | | | |
| Operating taxes and licenses | | | 1,033 | | | | 1,927 | | | | 84 | | | | 1,732 | | | | | |
| Insurance and claims | | | 19,964 | | | | 15,221 | | | | 361 | | | | 666 | | | | | |
| Communications and utilities | | | 1 | | | | 583 | | | | 25 | | | | 716 | | | | | |
| General supplies and expenses | | | 704 | | | | 1,616 | | | | 2,444 | | | | 13,308 | | | | | |
| Depreciation and amortization | | | 4 | | | | 12,658 | | | | 65 | | | | 1,419 | | | | | |
| Loss on disposition of property and equipment, net | | | - | | | | 225 | | | | - | | | | - | | | | | |
| Total allocated overhead | | | 25,830 | | | | 29,308 | | | | 6,870 | | | | 7,019 | | | | | |
| Segment operating expenses | | | 268,490 | | | | 288,634 | | | | 195,658 | | | | 68,636 | | | | 821,418 | |
| Segment operating income | | $ | 18,135 | | | $ | 12,272 | | | $ | 10,962 | | | $ | 6,258 | | | $ | 47,680 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (20,564 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 27,116 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (8,795 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 11,622 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 29,943 | |
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