Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Results of Operations
Gross revenues									$ 1,207,510	$ 1,316,466	$ 1,354,230
Less: Inter-segment revenues									1,197,509	1,311,917	1,343,135
Revenues									1,197,509	1,311,917	1,343,135
Gross profit	$ 23,127	$ (2,614)	$ 28,212	$ 32,278	$ 34,099	$ 27,303	$ 30,005	$ 34,584	81,003	125,991	87,370
Operating income (loss)	3,531	$ (21,210)	$ 8,237	$ 14,301	14,499	$ 6,347	$ 4,935	$ 15,101	4,859	40,882	8,802
Segment assets	586,030				564,967				586,030	564,967	561,689
Capital expenditures									11,908	13,939	15,773
Depreciation and amortization									21,602	21,441	23,480
Electrical Infrastructure [Member]
Results of Operations
Gross revenues									373,384	349,011	257,930
Less: Inter-segment revenues									373,384	349,011	257,930
Revenues									373,384	349,011	257,930
Gross profit									7,137	29,301	(31,444)
Operating income (loss)									(8,309)	11,144	(44,293)
Segment assets	183,351				135,298				183,351	135,298	129,725
Capital expenditures									1,390	1,611	579
Depreciation and amortization									5,198	5,008	4,915
Oil Gas & Chemical [Member]
Results of Operations
Gross revenues									247,423	252,973	310,826
Less: Inter-segment revenues									240,523	249,795	305,360
Revenues									240,523	249,795	305,360
Gross profit									12,675	18,553	25,394
Operating income (loss)									(8,783)	(3,503)	7,064
Segment assets	129,177				91,350				129,177	91,350	108,960
Capital expenditures									829	1,481	3,858
Depreciation and amortization									6,299	4,811	4,772
Storage Solutions [Member]
Results of Operations
Gross revenues									483,254	564,738	504,155
Less: Inter-segment revenues									481,696	563,512	503,123
Revenues									481,696	563,512	503,123
Gross profit									55,651	67,843	58,085
Operating income (loss)									22,928	33,449	29,069
Segment assets	166,742				201,875				166,742	201,875	172,857
Capital expenditures									2,017	3,882	2,396
Depreciation and amortization									7,277	8,124	7,298
Industrial [Member]
Results of Operations
Gross revenues									103,449	149,744	281,319
Less: Inter-segment revenues									101,906	149,599	276,722
Revenues									101,906	149,599	276,722
Gross profit									5,540	10,294	35,335
Operating income (loss)									(977)	(208)	16,962
Segment assets	53,754				67,569				53,754	67,569	102,761
Capital expenditures									38	104	1,139
Depreciation and amortization									2,828	3,498	6,495
Unallocated Corporate [Member]
Results of Operations
Segment assets	$ 53,006				$ 68,875				53,006	68,875	47,386
Capital expenditures									7,634	6,861	7,801
Intersegment Eliminations [Member]
Results of Operations
Less: Inter-segment revenues									10,001	4,549	11,095
Revenues									10,001	4,549	11,095
Intersegment Eliminations [Member] | Electrical Infrastructure [Member]
Results of Operations
Less: Inter-segment revenues									0	0	0
Revenues									0	0	0
Intersegment Eliminations [Member] | Oil Gas & Chemical [Member]
Results of Operations
Less: Inter-segment revenues									6,900	3,178	5,466
Revenues									6,900	3,178	5,466
Intersegment Eliminations [Member] | Storage Solutions [Member]
Results of Operations
Less: Inter-segment revenues									1,558	1,226	1,032
Revenues									1,558	1,226	1,032
Intersegment Eliminations [Member] | Industrial [Member]
Results of Operations
Less: Inter-segment revenues									1,543	145	4,597
Revenues									$ 1,543	$ 145	$ 4,597