v3.26.1
Revenue - Disaggregation of Gross Revenues by Major Service Lines and Geographic Markets and Timing of Revenue Recognition (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
Disaggregation Of Revenue [Line Items]        
Revenues $ 214,135 $ 214,007 $ 672,920 $ 682,116
Transportation Services        
Disaggregation Of Revenue [Line Items]        
Revenues 202,400 202,386 633,280 646,269
Value Added Services        
Disaggregation Of Revenue [Line Items]        
Revenues [1] 11,735 11,621 39,640 35,847
Services Transferred over Time        
Disaggregation Of Revenue [Line Items]        
Revenues 213,017 212,640 668,088 677,358
Services Transferred at a Point in Time        
Disaggregation Of Revenue [Line Items]        
Revenues 1,118 1,367 4,832 4,758
Operating Segments | United States        
Disaggregation Of Revenue [Line Items]        
Revenues 188,608 186,010 589,747 599,588
Operating Segments | United States | Transportation Services        
Disaggregation Of Revenue [Line Items]        
Revenues 184,499 182,034 577,276 587,774
Operating Segments | United States | Value Added Services        
Disaggregation Of Revenue [Line Items]        
Revenues [1] 4,109 3,976 12,471 11,814
Operating Segments | United States | Services Transferred over Time        
Disaggregation Of Revenue [Line Items]        
Revenues 187,588 184,698 585,166 594,950
Operating Segments | United States | Services Transferred at a Point in Time        
Disaggregation Of Revenue [Line Items]        
Revenues 1,020 1,312 4,581 4,638
Operating Segments | Canada        
Disaggregation Of Revenue [Line Items]        
Revenues 25,729 28,085 83,595 82,745
Operating Segments | Canada | Transportation Services        
Disaggregation Of Revenue [Line Items]        
Revenues 18,103 20,440 56,426 58,712
Operating Segments | Canada | Value Added Services        
Disaggregation Of Revenue [Line Items]        
Revenues [1] 7,626 7,645 27,169 24,033
Operating Segments | Canada | Services Transferred over Time        
Disaggregation Of Revenue [Line Items]        
Revenues 25,631 28,030 83,344 82,625
Operating Segments | Canada | Services Transferred at a Point in Time        
Disaggregation Of Revenue [Line Items]        
Revenues 98 55 251 120
Corporate/Eliminations        
Disaggregation Of Revenue [Line Items]        
Revenues (202) (88) (422) (217)
Corporate/Eliminations | Transportation Services        
Disaggregation Of Revenue [Line Items]        
Revenues (202) (88) (422) (217)
Corporate/Eliminations | Value Added Services        
Disaggregation Of Revenue [Line Items]        
Revenues [1] 0 0 0 0
Corporate/Eliminations | Services Transferred over Time        
Disaggregation Of Revenue [Line Items]        
Revenues (202) (88) (422) (217)
Corporate/Eliminations | Services Transferred at a Point in Time        
Disaggregation Of Revenue [Line Items]        
Revenues $ 0 $ 0 $ 0 $ 0
[1] Value-added services include MM&D, CHB, GTM, and other services.