Segment Information - Results of Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013
Segment Reporting Information [Line Items]
Gross revenues	$ 226,906	$ 210,760
Consolidated revenues	226,217	209,608
Gross profit	25,476	22,244
Operating income	10,762	7,924
Segment assets	428,988	362,850	409,978
Electrical Infrastructure [Member]
Segment Reporting Information [Line Items]
Gross revenues	32,877	33,270
Consolidated revenues	32,877	33,270
Gross profit	3,330	4,706
Operating income	1,300	2,319
Segment assets	59,018	56,826
Oil Gas & Chemical [Member]
Segment Reporting Information [Line Items]
Gross revenues	62,792	67,097
Consolidated revenues	62,495	67,097
Gross profit	7,531	7,867
Operating income	3,263	3,775
Segment assets	79,513	71,848
Storage Solutions [Member]
Segment Reporting Information [Line Items]
Gross revenues	108,546	105,418
Consolidated revenues	108,154	104,266
Gross profit	12,837	9,969
Operating income	5,832	3,449
Segment assets	157,389	186,600
Industrial [Member]
Segment Reporting Information [Line Items]
Gross revenues	22,691	4,975
Consolidated revenues	22,691	4,975
Gross profit	1,778	(298)
Operating income	367	(1,619)
Segment assets	35,801	14,179
All Other Segments [Member]
Segment Reporting Information [Line Items]
Segment assets	97,267	33,397
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Gross revenues	689	1,152
Intersegment Eliminations [Member] \| Electrical Infrastructure [Member]
Segment Reporting Information [Line Items]
Gross revenues	0	0
Intersegment Eliminations [Member] \| Oil Gas & Chemical [Member]
Segment Reporting Information [Line Items]
Gross revenues	297	0
Intersegment Eliminations [Member] \| Storage Solutions [Member]
Segment Reporting Information [Line Items]
Gross revenues	392	1,152
Intersegment Eliminations [Member] \| Industrial [Member]
Segment Reporting Information [Line Items]
Gross revenues	$ 0	$ 0

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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