v3.26.1
Significant Accounting Policies - Concentration of Risks (Details) - Revenues - Customer Concentration Risk
3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Private        
Concentration Risk [Line Items]        
Concentration risk percentage 34.90% 35.10% 33.60% 39.00%
Public        
Concentration Risk [Line Items]        
Concentration risk percentage 65.10% 64.90% 66.40% 61.00%
Florida Department of Transportation        
Concentration Risk [Line Items]        
Concentration risk percentage 10.50%   11.30%