Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2021
Segment Reporting Information [Line Items]
Gross revenues	$ 164,396	$ 169,204	$ 335,122	$ 354,199
Revenue	161,965	167,468	330,058	350,239
Gross profit (loss)	3,207	15,313	(301)	29,663
Selling, general and administrative expenses	15,922	16,724	32,551	34,852
Restructuring costs	695	5,045	1,300	4,725
Operating income (loss)	(13,410)	(6,456)	(34,152)	(9,914)
Segment assets	440,564		440,564		$ 467,556
Utility and Power Infrastructure
Segment Reporting Information [Line Items]
Gross revenues	54,752	52,023	111,956	112,694
Revenue	54,752	52,023	111,956	112,694
Gross profit (loss)	(491)	5,597	(6,598)	12,510
Selling, general and administrative expenses	3,150	2,576	6,200	4,798
Restructuring costs	37	812	46	823
Operating income (loss)	(3,678)	2,209	(12,844)	6,889
Segment assets	92,072		92,072		81,717
Process and Industrial Facilities
Segment Reporting Information [Line Items]
Gross revenues	52,037	51,747	97,247	98,475
Revenue	50,316	51,262	94,221	97,193
Gross profit (loss)	4,235	7,864	7,106	11,523
Selling, general and administrative expenses	2,792	3,387	5,554	7,437
Restructuring costs	(24)	3,364	(17)	2,864
Operating income (loss)	1,467	1,113	1,569	1,222
Segment assets	78,757		78,757		106,619
Storage and Terminal Solutions
Segment Reporting Information [Line Items]
Gross revenues	57,607	65,434	125,919	143,030
Revenue	56,897	64,183	123,881	140,352
Gross profit (loss)	(172)	1,852	241	5,630
Selling, general and administrative expenses	4,280	3,919	8,786	9,062
Restructuring costs	107	641	74	654
Operating income (loss)	(4,559)	(2,708)	(8,619)	(4,086)
Segment assets	149,523		149,523		160,782
Corporate
Segment Reporting Information [Line Items]
Gross profit (loss)	(365)	0	(1,050)	0
Selling, general and administrative expenses	5,700	6,842	12,011	13,555
Restructuring costs	575	228	1,197	384
Operating income (loss)	(6,640)	(7,070)	(14,258)	(13,939)
Segment assets	120,212		120,212		$ 118,438
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Gross revenues	2,431	1,736	5,064	3,960
Intersegment Eliminations [Member] | Process and Industrial Facilities
Segment Reporting Information [Line Items]
Gross revenues	1,721	485	3,026	1,282
Intersegment Eliminations [Member] | Storage and Terminal Solutions
Segment Reporting Information [Line Items]
Gross revenues	$ 710	$ 1,251	$ 2,038	$ 2,678