Segment Information - Results of Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended				3 Months Ended			9 Months Ended				3 Months Ended			9 Months Ended				3 Months Ended			9 Months Ended				3 Months Ended			9 Months Ended								3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Mar. 31, 2014		Mar. 31, 2013	Jun. 30, 2013	Mar. 31, 2014 Electrical Infrastructure [Member]		Mar. 31, 2013 Electrical Infrastructure [Member]	Mar. 31, 2014 Electrical Infrastructure [Member]		Mar. 31, 2013 Electrical Infrastructure [Member]	Jun. 30, 2013 Electrical Infrastructure [Member]	Mar. 31, 2014 Oil Gas & Chemical [Member]		Mar. 31, 2013 Oil Gas & Chemical [Member]	Mar. 31, 2014 Oil Gas & Chemical [Member]		Mar. 31, 2013 Oil Gas & Chemical [Member]	Jun. 30, 2013 Oil Gas & Chemical [Member]	Mar. 31, 2014 Storage Solutions [Member]		Mar. 31, 2013 Storage Solutions [Member]	Mar. 31, 2014 Storage Solutions [Member]		Mar. 31, 2013 Storage Solutions [Member]	Jun. 30, 2013 Storage Solutions [Member]	Mar. 31, 2014 Industrial [Member]		Mar. 31, 2013 Industrial [Member]	Mar. 31, 2014 Industrial [Member]		Mar. 31, 2013 Industrial [Member]	Jun. 30, 2013 Industrial [Member]	Mar. 31, 2014 Other Segments [Member]		Jun. 30, 2013 Other Segments [Member]	Mar. 31, 2013 Other Segments [Member]	Mar. 31, 2014 Intersegment Eliminations [Member]	Mar. 31, 2013 Intersegment Eliminations [Member]	Mar. 31, 2014 Intersegment Eliminations [Member]	Mar. 31, 2013 Intersegment Eliminations [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Electrical Infrastructure [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Electrical Infrastructure [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Electrical Infrastructure [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Electrical Infrastructure [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Oil Gas & Chemical [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Oil Gas & Chemical [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Oil Gas & Chemical [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Oil Gas & Chemical [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Storage Solutions [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Storage Solutions [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Storage Solutions [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Storage Solutions [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Industrial [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Industrial [Member]	Mar. 31, 2014 Intersegment Eliminations [Member] Industrial [Member]	Mar. 31, 2013 Intersegment Eliminations [Member] Industrial [Member]	Dec. 21, 2013 Kvaerner NAC	Mar. 31, 2014 Kvaerner NAC Electrical Infrastructure [Member]		Mar. 31, 2014 Kvaerner NAC Oil Gas & Chemical [Member]		Mar. 31, 2014 Kvaerner NAC Industrial [Member]		Mar. 31, 2014 Kvaerner NAC Other Segments [Member]
Segment Reporting Information [Line Items]
Gross revenues	$ 381,962		$ 226,388	$ 919,954		$ 659,122		$ 62,144		$ 41,709	$ 132,201		$ 125,102		$ 63,112		$ 73,638	$ 188,025		$ 207,370		$ 182,129		$ 95,200	$ 471,330		$ 298,801		$ 74,577		$ 15,841	$ 128,398		$ 27,849						$ 446	$ 418	$ 1,223	$ 2,108	$ 0	$ 0	$ 0	$ 0	$ 118	$ 44	$ 425	$ 44	$ 328	$ 374	$ 798	$ 2,064	$ 0	$ 0	$ 0	$ 0
Consolidated revenues	381,516		225,970	918,731		657,014		62,144		41,709	132,201		125,102		62,994		73,594	187,600		207,326		181,801		94,826	470,532		296,737		74,577		15,841	128,398		27,849
Gross profit	39,944		23,126	99,570		67,703		5,971		4,994	13,155		16,329		7,397		8,016	21,614		23,928		19,269		8,828	51,894		26,545		7,307		1,288	12,907		901
Operating income	18,819		8,431	44,398		25,127		2,498		2,424	4,658		8,439		3,252		3,285	8,922		10,987		10,084		2,447	26,676		7,446		2,985		275	4,142		(1,745)
Segment assets	597,815	[1]	379,175	597,815	[1]	379,175	409,978	98,502	[1]	58,640	98,502	[1]	58,640		83,505	[1]	84,499	83,505	[1]	84,499		220,155	[1]	155,739	220,155	[1]	155,739		122,013	[1]	23,683	122,013	[1]	23,683		73,640	[1]		56,614																						34,800	[1]	2,800	[1]	78,900	[1]
Goodwill	$ 66,589			$ 66,589			$ 30,836	$ 12,013			$ 12,013			$ 12,013	$ 5,088			$ 5,088			$ 5,088	$ 9,940			$ 9,940			$ 10,063	$ 3,672			$ 3,672			$ 3,672	$ 35,876		$ 0																						$ 36,176							$ 35,900

[1] balances include the assets of Matrix NAC and are allocated to the Electrical Infrastructure, Oil Gas & Chemical, and Industrial segments in the amounts of $34.8 million, $2.8 million and $78.9 million, respectively. Unallocated assets includes $35.9 million of Goodwill related to the acquisition. As previously noted, we are currently assessing the impact of the acquisition on our reporting units and expect to complete the Goodwill analysis in the fourth quarter of fiscal 2014.