| Segment Reporting [Table Text Block] |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Three Months Ended June 30, 2026 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 73,742 | | | $ | 94,020 | | | $ | 99,542 | | | $ | 26,722 | | | $ | 294,026 | |
| Fuel surcharge revenue(1) | | | 19,678 | | | | 18,346 | | | | - | | | | 156 | | | | 38,180 | |
| Subtotal operating revenues | | $ | 93,420 | | | $ | 112,366 | | | $ | 99,542 | | | $ | 26,878 | | | $ | 332,206 | |
| Other revenues | | | | | | | | | | | | | | | | | | | 667 | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 332,873 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 27,631 | | | | 44,748 | | | | 3,931 | | | | 13,823 | | | | | |
| Fuel expense | | | 18,189 | | | | 19,094 | | | | - | | | | 245 | | | | | |
| Operations and maintenance | | | 8,924 | | | | 11,701 | | | | 765 | | | | 1,828 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 14,825 | | | | 6,956 | | | | 88,802 | | | | 1,109 | | | | | |
| Operating taxes and licenses | | | 273 | | | | 742 | | | | 13 | | | | 430 | | | | | |
| Insurance and claims | | | 6,312 | | | | 5,589 | | | | 706 | | | | 246 | | | | | |
| Communications and utilities | | | 1 | | | | 226 | | | | 34 | | | | 292 | | | | | |
| General supplies and expenses | | | 452 | | | | 400 | | | | 1,165 | | | | 4,062 | | | | | |
| Depreciation and amortization | | | - | | | | 4,924 | | | | 102 | | | | 425 | | | | | |
| Loss on disposition of property and equipment, net | | | - | | | | 13 | | | | - | | | | - | | | | | |
| Total allocated overhead | | | 8,427 | | | | 10,195 | | | | 2,285 | | | | 2,844 | | | | | |
| Segment operating expenses | | | 85,034 | | | | 104,588 | | | | 97,803 | | | | 25,304 | | | | 312,729 | |
| Subtotal operating income | | $ | 8,386 | | | $ | 7,778 | | | $ | 1,739 | | | $ | 1,574 | | | $ | 20,144 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (11,303 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 8,841 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (2,981 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 5,265 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 11,125 | |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Three Months Ended June 30, 2025 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 83,229 | | | $ | 90,166 | | | $ | 77,550 | | | $ | 25,587 | | | $ | 276,532 | |
| Fuel surcharge revenue(1) | | | 14,071 | | | | 12,111 | | | | - | | | | 140 | | | | 26,322 | |
| Subtotal operating revenues | | $ | 97,300 | | | $ | 102,277 | | | $ | 77,550 | | | $ | 25,727 | | | $ | 302,854 | |
| Other revenues | | | | | | | | | | | | | | | | | | | - | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 302,854 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 32,153 | | | | 42,041 | | | | 2,844 | | | | 12,350 | | | | | |
| Fuel expense | | | 14,335 | | | | 13,552 | | | | - | | | | 156 | | | | | |
| Operations and maintenance | | | 10,322 | | | | 11,300 | | | | 563 | | | | 1,534 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 17,136 | | | | 9,230 | | | | 66,558 | | | | 1,173 | | | | | |
| Operating taxes and licenses | | | 341 | | | | 652 | | | | 9 | | | | 559 | | | | | |
| Insurance and claims | | | 6,743 | | | | 5,170 | | | | 25 | | | | 239 | | | | | |
| Communications and utilities | | | - | | | | 224 | | | | 8 | | | | 227 | | | | | |
| General supplies and expenses | | | 225 | | | | 631 | | | | 885 | | | | 4,742 | | | | | |
| Depreciation and amortization | | | 1 | | | | 4,222 | | | | 22 | | | | 476 | | | | | |
| Gain on disposition of property and equipment, net | | | - | | | | 207 | | | | - | | | | - | | | | | |
| Total allocated overhead | | | 8,578 | | | | 8,835 | | | | 2,174 | | | | 2,355 | | | | | |
| Segment operating expenses | | | 89,834 | | | | 96,064 | | | | 73,088 | | | | 23,811 | | | | 282,797 | |
| Segment operating income | | $ | 7,466 | | | $ | 6,213 | | | $ | 4,462 | | | $ | 1,916 | | | $ | 20,057 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (8,494 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 11,563 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (2,470 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 4,268 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 13,361 | |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Six Months Ended June 30, 2026 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 145,691 | | | $ | 185,084 | | | $ | 190,273 | | | $ | 54,274 | | | $ | 575,322 | |
| Fuel surcharge revenue(1) | | | 32,400 | | | | 30,705 | | | | - | | | | 311 | | | | 63,416 | |
| Subtotal operating revenues | | $ | 178,091 | | | $ | 215,789 | | | $ | 190,273 | | | $ | 54,585 | | | $ | 638,738 | |
| Other revenues | | | | | | | | | | | | | | | | | | | 1,296 | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 640,034 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 55,655 | | | | 88,992 | | | | 7,103 | | | | 28,563 | | | | | |
| Fuel expense | | | 32,699 | | | | 33,256 | | | | - | | | | 463 | | | | | |
| Operations and maintenance | | | 18,225 | | | | 22,811 | | | | 1,266 | | | | 3,682 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 29,907 | | | | 14,154 | | | | 168,172 | | | | 2,305 | | | | | |
| Operating taxes and licenses | | | 561 | | | | 1,463 | | | | 45 | | | | 869 | | | | | |
| Insurance and claims | | | 12,962 | | | | 11,199 | | | | 1,174 | | | | 489 | | | | | |
| Communications and utilities | | | 1 | | | | 447 | | | | 68 | | | | 670 | | | | | |
| General supplies and expenses | | | 807 | | | | 794 | | | | 2,394 | | | | 8,010 | | | | | |
| Depreciation and amortization | | | 1 | | | | 9,798 | | | | 201 | | | | 848 | | | | | |
| Loss on disposition of property and equipment, net | | | - | | | | 13 | | | | - | | | | - | | | | | |
| Total allocated overhead | | | 16,066 | | | | 19,497 | | | | 4,408 | | | | 5,334 | | | | | |
| Segment operating expenses | | | 166,884 | | | | 202,424 | | | | 184,831 | | | | 51,233 | | | | 605,372 | |
| Segment operating income | | $ | 11,207 | | | $ | 13,365 | | | $ | 5,442 | | | $ | 3,352 | | | $ | 34,662 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (19,539 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 15,123 | |
| Interest expense, net | | | | | | | | | | | | | | | | | | | (6,867 | ) |
| Income from equity method investment | | | | | | | | | | | | | | | | | | | 8,952 | |
| Income before income taxes | | | | | | | | | | | | | | | | | | $ | 17,208 | |
| (in thousands) | | | | | | | | | | | | | | | | | | | | |
| Six Months Ended June 30, 2025 | | Expedited | | | Dedicated | | | Managed Freight | | | Warehousing | | | Total | |
| Revenues | | | | | | | | | | | | | | | | | | | | |
| Freight revenue | | $ | 163,478 | | | $ | 172,246 | | | $ | 134,400 | | | $ | 49,627 | | | $ | 519,751 | |
| Fuel surcharge revenue(1) | | | 28,515 | | | | 23,640 | | | | - | | | | 303 | | | | 52,458 | |
| Subtotal operating revenues | | $ | 191,993 | | | $ | 195,886 | | | $ | 134,400 | | | $ | 49,930 | | | $ | 572,209 | |
| Other revenues | | | | | | | | | | | | | | | | | | | - | |
| Total revenue | | | | | | | | | | | | | | | | | | $ | 572,209 | |
| | | | | | | | | | | | | | | | | | | | | |
| Operating expenses: | | | | | | | | | | | | | | | | | | | | |
| Salaries, wages, and related expenses | | | 63,642 | | | | 81,400 | | | | 5,122 | | | | 23,777 | | | | | |
| Fuel expense | | | 29,270 | | | | 26,662 | | | | - | | | | 331 | | | | | |
| Operations and maintenance | | | 21,165 | | | | 21,915 | | | | 506 | | | | 2,683 | | | | | |
| Revenue equipment rentals and purchased transportation | | | 33,697 | | | | 17,574 | | | | 114,189 | | | | 2,251 | | | | | |
| Operating taxes and licenses | | | 677 | | | | 1,260 | | | | 66 | | | | 1,349 | | | | | |
| Insurance and claims | | | 13,317 | | | | 10,163 | | | | 157 | | | | 446 | | | | | |
| Communications and utilities | | | 1 | | | | 387 | | | | 18 | | | | 467 | | | | | |
| General supplies and expenses | | | 469 | | | | 1,134 | | | | 1,675 | | | | 9,146 | | | | | |
| Depreciation and amortization | | | 3 | | | | 8,289 | | | | 43 | | | | 957 | | | | | |
| Gain on disposition of property and equipment, net | | | - | | | | 288 | | | | - | | | | - | | | | | |
| Total allocated overhead | | | 16,696 | | | | 18,554 | | | | 4,622 | | | | 4,763 | | | | | |
| Segment operating expenses | | | 178,937 | | | | 187,626 | | | | 126,398 | | | | 46,170 | | | | 539,131 | |
| Segment operating income | | $ | 13,056 | | | $ | 8,260 | | | $ | 8,002 | | | $ | 3,760 | | | $ | 33,078 | |
| Other (2) | | | | | | | | | | | | | | | | | | | (13,888 | ) |
| Total consolidated operating income | | | | | | | | | | | | | | | | | | | 19,190 | |
|