Results of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Jun. 30, 2012
Operating Statistics [Line Items]
Gross revenues	$ 210,760	$ 170,508
Inter-segment revenues	1,152	1,187
Consolidated revenues	209,608	169,321
Gross profit	22,244	18,093
Operating income	7,924	6,610
Segment assets	362,850	299,273	323,135
Electrical Infrastructure [Member]
Operating Statistics [Line Items]
Gross revenues	33,270	22,012
Inter-segment revenues
Consolidated revenues	33,270	22,012
Gross profit	4,706	2,785
Operating income	2,319	729
Segment assets	56,826	40,550
Oil Gas & Chemical [Member]
Operating Statistics [Line Items]
Gross revenues	67,097	45,999
Inter-segment revenues		175
Consolidated revenues	67,097	45,824
Gross profit	7,867	4,347
Operating income	3,775	1,412
Segment assets	71,848	54,036
Storage Solutions [Member]
Operating Statistics [Line Items]
Gross revenues	105,418	95,922
Inter-segment revenues	1,152	1,012
Consolidated revenues	104,266	94,910
Gross profit	9,969	10,387
Operating income	3,449	4,226
Segment assets	186,600	139,820
Industrial [Member]
Operating Statistics [Line Items]
Gross revenues	4,975	6,575
Inter-segment revenues
Consolidated revenues	4,975	6,575
Gross profit	(298)	574
Operating income	(1,619)	243
Segment assets	14,179	17,949
Other [Member]
Operating Statistics [Line Items]
Segment assets	$ 33,397	$ 46,918