Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2020
Segment Reporting Information [Line Items]
Gross revenues	$ 149,357	$ 250,678	$ 503,556	$ 910,790
Revenue	148,260	248,327	498,499	905,101
Gross profit (loss)	1,560	20,477	31,223	82,943
Selling, general and administrative expenses	17,179	19,718	52,031	66,574
Restructuring costs	1,860	6,559	6,585	45,074
Operating income (loss)	(17,479)	(5,800)	(27,393)	(28,705)
Segment assets	471,677		471,677		$ 517,310
Utility and Power Infrastructure [Member]
Segment Reporting Information [Line Items]
Gross revenues	44,720	55,670	157,414	152,552
Revenue	44,720	55,670	157,414	152,552
Gross profit (loss)	(4,692)	3,138	7,818	1,744
Selling, general and administrative expenses	2,356	2,081	7,154	7,491
Restructuring costs	403	935	1,226	25,835
Operating income (loss)	(7,451)	122	(562)	(31,582)
Segment assets	81,625		81,625		67,398
Process and Industrial Facilities
Segment Reporting Information [Line Items]
Gross revenues	43,095	76,297	141,570	375,518
Revenue	42,834	74,970	140,027	372,730
Gross profit (loss)	(171)	3,070	11,352	30,498
Selling, general and administrative expenses	3,882	5,343	11,319	19,666
Restructuring costs	781	4,087	3,645	17,702
Operating income (loss)	(4,834)	(6,360)	(3,612)	(6,870)
Segment assets	116,140		116,140		138,734
Storage and Terminal Solutions
Segment Reporting Information [Line Items]
Gross revenues	61,542	118,711	204,572	382,720
Revenue	60,706	117,687	201,058	379,819
Gross profit (loss)	6,423	14,907	12,053	52,675
Selling, general and administrative expenses	4,792	6,165	13,854	19,942
Restructuring costs	590	821	1,244	821
Operating income (loss)	1,041	7,921	(3,045)	31,912
Segment assets	164,652		164,652		187,167
Corporate [Member]
Segment Reporting Information [Line Items]
Gross profit (loss)	0	(638)	0	(1,974)
Selling, general and administrative expenses	6,149	6,129	19,704	19,475
Restructuring costs	86	716	470	716
Operating income (loss)	(6,235)	(7,483)	(20,174)	(22,165)
Segment assets	109,260		109,260		$ 124,011
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Gross revenues	1,097	2,351	5,057	5,689
Intersegment Eliminations [Member] | Process and Industrial Facilities
Segment Reporting Information [Line Items]
Gross revenues	261	1,327	1,543	2,788
Intersegment Eliminations [Member] | Storage and Terminal Solutions
Segment Reporting Information [Line Items]
Gross revenues	$ 836	$ 1,024	$ 3,514	$ 2,901