v3.26.1
SHORT-TERM AND LONG-TERM DEBT - Summary of short-term and long-term debt (Narrative) (Details) - USD ($)
 6 Months Ended 12 Months Ended
Jun. 28, 2025
Mar. 31, 2026
Sep. 30, 2025
Apr. 30, 2023
Apr. 27, 2020
Apr. 07, 2020
SHORT-TERM AND LONG-TERM DEBT            
Fair value of debt   $ 31,100,000 $ 42,800,000      
Line of credit payable to bank, final payment due by June 28, 2027            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate at period end (as a percent)   6.75% 7.50%      
Maximum capacity $ 30,000,000          
Line of credit payable to bank, final payment due by June 28, 2027 | Minimum            
SHORT-TERM AND LONG-TERM DEBT            
Variable interest rate on line of credit (as a percent) 4.99%          
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:PrimeRateMember          
Equipment line of credit, Final payment due February 2028            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   7.25% 7.25%      
Maximum capacity   $ 9,300,000 $ 9,300,000      
Monthly or annual installments   $ 202,809 $ 202,809      
Paycheck Protection Program loans from Small Business Administration            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   1.00% 1.00%      
Debt instrument face amount       $ 9,800,000 $ 9,800,000 $ 13,100,000
Term note payable to United Bank, WV Pipeline acquisition, final payment due by March 25, 2026            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   4.25% 4.25%      
Monthly or annual installments   $ 64,853 $ 64,853      
Notes Payable To Finance Companies Due April 2026 through February 2030            
SHORT-TERM AND LONG-TERM DEBT            
Monthly or annual installments   $ 281,000 $ 244,000      
Notes Payable To Finance Companies Due April 2026 through February 2030 | Minimum            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   0.00% 0.00%      
Notes Payable To Finance Companies Due April 2026 through February 2030 | Maximum            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   6.00% 6.00%      
Note payable to United Bank Tribute acquisition finance final payment due by December 2030            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   6.90%        
Monthly or annual installments   $ 272,016        
Notes payable to bank, final payment due November 2034            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   4.82%        
Monthly or annual installments   $ 7,848        
Notes payable to bank, final payment due by October 2027            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   6.00%        
Monthly or annual installments   $ 59,932        
Convertible equipment line of credit            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   8.50% 8.50%      
Maximum capacity   $ 5,000,000 $ 5,000,000      
Variable interest rate on line of credit (as a percent)   2.75% 2.75%      
Debt term   48 months 48 months      
Unsecured notes payable to Joe and Cathy Rigney, due September 30, 2030            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   5.00% 5.00%      
Monthly or annual installments   $ 500,000 $ 500,000      
Debt term   5 years 5 years      
Fair value of debt     $ 462,950,000      
Notes payable to David Bolton and Daniel Bolton due final payment December 31, 2025            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)     3.25%      
Monthly or annual installments     $ 500,000      
Note payable to United Bank, Tri-State Paving acquisition, final payment due by June 1, 2027            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   4.50% 4.50%      
Monthly or annual installments   $ 129,910 $ 129,910      
Notes payable to Corns Enterprises, final payment due April 29, 2026            
SHORT-TERM AND LONG-TERM DEBT            
Interest rate, fixed (as a percent)   3.50% 3.50%      
REPLACED WITH US-GAAP Notes payable on annual installments   $ 250,000 $ 250,000      
Fair value of debt   936,000        
Debt instrument face amount   $ 1,000,000 $ 1,000,000