Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Revenue, Performance Obligation [Abstract]
Revenue, Remaining Performance Obligation, Amount		$ 459,700
Performance obligations to be recognized as revenue within next twelve months		381,000
Contract with Customer, Asset and Liability [Abstract]
Costs and estimated earnings in excess of billings on uncompleted contracts	$ 44,752	44,888	$ 44,752
Change in costs and estimated earnings in excess of billings on uncompleted contracts		136
Billings on uncompleted contracts in excess of costs and estimated earnings	(65,106)	(85,436)	(65,106)
Change in billings on uncompleted contracts in excess of costs and estimated earnings		(20,330)
Contract with customer, current liability, net	(20,354)	(40,548)	(20,354)
Change in net contract balances		(20,194)
Disclosure Customer Contracts Additional Information [Abstract]
Contract with Customer, Liability, Revenue Recognized		57,900
Contract Receivable Retainage, Next Twelve Months	16,100	16,300	16,100
Contract Receivable Retainage, after Next Twelve Months	4,000	10,000	4,000
Disaggregation of Revenue [Line Items]
Revenue		795,020	707,780	$ 673,398
Loss Contingency, Receivable, Period Increase (Decrease)				2,900
Loss Contingency, Receivable, Proceeds				8,900
Process and Industrial Facilities
Disaggregation of Revenue [Line Items]
Revenue		369,823	254,848	199,917
Loss on Contracts		12,600	8,700
Utility and Power Infrastructure Member
Disaggregation of Revenue [Line Items]
Loss on Contracts				5,800
Storage and Terminal Solutions
Disaggregation of Revenue [Line Items]
Revenue		255,693	232,839	263,429
Loss on Contracts			6,300	3,800
Utility and Power Infrastructure Capital Project 1 [Member]
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress			3,600
Utility and Power Infrastructure Capital Project 2 [Member]
Disaggregation of Revenue [Line Items]
Revenue			78,100
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	$ 2,200		100
Utility and Power Infrastructure Project 3 [Member]
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress			2,100
Fixed-price Contract
Disaggregation of Revenue [Line Items]
Revenue		419,426	421,188	444,042
Time-and-materials Contract
Disaggregation of Revenue [Line Items]
Revenue		375,594	286,592	229,356
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue		720,140	640,512	604,739
CANADA
Disaggregation of Revenue [Line Items]
Revenue		61,691	63,045	61,703
Other international [Member]
Disaggregation of Revenue [Line Items]
Revenue		$ 13,189	$ 4,223	$ 6,956