Quarterly report pursuant to Section 13 or 15(d)

Segment Reporting (Details)

v3.8.0.1
Segment Reporting (Details)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Segment Reporting Information [Line Items]          
External revenues $ 280,201 $ 249,552 $ 794,700 $ 717,737  
Depreciation and amortization 10,326 9,399 30,578 28,409  
Share-based compensation expense 1,939 2,093 5,965 6,204  
Interest expense 288 216 806 1,230  
Operating Income (Loss) 26,898 24,700 79,896 31,756  
Total assets 669,168 641,513 669,168 641,513 $ 641,291
Capital expenditures 8,948 12,684 $ 13,610 28,725  
Number of reportable segments     4    
Expedited LTL [Member]          
Segment Reporting Information [Line Items]          
External revenues 155,006 143,753 $ 446,658 421,194  
Intersegment revenues 697 584 1,913 2,216  
Depreciation and amortization 5,438 5,470 16,521 16,278  
Share-based compensation expense 1,604 1,792 4,980 5,353  
Interest expense 1 385 2 1,345  
Operating Income (Loss) 23,204 21,014 64,596 63,026  
Total assets 633,914 634,028 633,914 634,028  
Capital expenditures 8,372 11,915 12,640 24,487  
Truckload Expedited [Member]          
Segment Reporting Information [Line Items]          
External revenues 43,865 41,927 128,666 119,574  
Intersegment revenues 2,076 283 4,246 696  
Depreciation and amortization 1,546 1,470 4,694 4,944  
Share-based compensation expense 101 98 281 260  
Operating Income (Loss) 136 2,038 3,699 (36,679)  
Total assets 59,657 52,465 59,657 52,465  
Capital expenditures 7 36 15 1,821  
Pool Distribution [Member]          
Segment Reporting Information [Line Items]          
External revenues 39,122 36,305 113,639 100,726  
Intersegment revenues 58 132 199 427  
Depreciation and amortization 1,652 1,472 5,067 4,434  
Share-based compensation expense 90 84 297 251  
Operating Income (Loss) 681 66 3,672 (191)  
Total assets 53,201 46,327 53,201 46,327  
Capital expenditures 239 722 524 2,275  
Intermodal [Member]          
Segment Reporting Information [Line Items]          
External revenues 42,208 27,567 105,737 76,243  
Intersegment revenues 84 12 116 148  
Depreciation and amortization 1,690 987 4,296 2,753  
Share-based compensation expense 144 119 407 340  
Interest expense 12 12 36 66  
Operating Income (Loss) 3,480 3,041 9,133 8,170  
Total assets 145,394 128,048 145,394 128,048  
Capital expenditures 330 11 431 142  
Elimination [Member]          
Segment Reporting Information [Line Items]          
Intersegment revenues (2,915) (1,011) (6,474) (3,487)  
Interest expense 275 (181) 768 (181)  
Operating Income (Loss) (603) (1,459) (1,204) (2,570)  
Total assets $ (222,998) $ (219,355) $ (222,998) $ (219,355)