v3.25.2
Revenue (Details) - USD ($)
$ in Thousands
 12 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2023
Revenue, Performance Obligation [Abstract]      
Revenue, Remaining Performance Obligation, Amount $ 1,000,000    
Performance obligations to be recognized as revenue within next twelve months 582,300    
Contract with Customer, Asset and Liability [Abstract]      
Costs and estimated earnings in excess of billings on uncompleted contracts 29,764 $ 33,893  
Change in costs and estimated earnings in excess of billings on uncompleted contracts (4,129)    
Billings on uncompleted contracts in excess of costs and estimated earnings (323,593) (171,308)  
Change in billings on uncompleted contracts in excess of costs and estimated earnings (152,285)    
Contract with customer, current liability, net (293,829) (137,415)  
Change in net contract balances (156,414)    
Disclosure Customer Contracts Additional Information [Abstract]      
Contract with Customer, Liability, Revenue Recognized 168,500    
Contract Receivable Retainage, Next Twelve Months 29,000 11,600  
Contract Receivable Retainage, after Next Twelve Months 61,500 28,600  
Disaggregation of Revenue [Abstract]      
Revenue 769,286 728,213 $ 795,020
Disaggregation of Revenue [Line Items]      
Revenue 769,286 728,213 795,020
Unpriced Change Orders and Claims 11,400 9,900  
Process and Industrial Facilities      
Disaggregation of Revenue [Abstract]      
Revenue 154,704 266,260 369,823
Loss on Contracts   12,600  
Disaggregation of Revenue [Line Items]      
Revenue 154,704 266,260 369,823
Loss on Contracts   12,600  
Fixed-price Contract      
Disaggregation of Revenue [Abstract]      
Revenue 560,717 455,548 419,426
Disaggregation of Revenue [Line Items]      
Revenue 560,717 455,548 419,426
Time-and-materials Contract      
Disaggregation of Revenue [Abstract]      
Revenue 208,569 272,665 375,594
Disaggregation of Revenue [Line Items]      
Revenue 208,569 272,665 375,594
UNITED STATES      
Disaggregation of Revenue [Abstract]      
Revenue 719,388 662,449 720,140
Disaggregation of Revenue [Line Items]      
Revenue 719,388 662,449 720,140
CANADA      
Disaggregation of Revenue [Abstract]      
Revenue 41,228 56,420 61,691
Disaggregation of Revenue [Line Items]      
Revenue 41,228 56,420 61,691
Other international [Member]      
Disaggregation of Revenue [Abstract]      
Revenue 8,670 9,344 13,189
Disaggregation of Revenue [Line Items]      
Revenue $ 8,670 $ 9,344 $ 13,189