Intangible Assets Including Goodwill - Carrying Value of Goodwill By Segment (Details) - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2018	Dec. 12, 2016
Goodwill [Line Items]
Goodwill	$ 113,501
Goodwill [Roll Forward]
Net balance at June 30, 2015	113,501
Translation adjustment	114
Net balance at March 31, 2018	113,615
Electrical Infrastructure [Member]
Goodwill [Line Items]
Goodwill	42,152
Goodwill [Roll Forward]
Net balance at June 30, 2015	42,152
Translation adjustment	30
Net balance at March 31, 2018	42,182
Oil Gas & Chemical [Member]
Goodwill [Line Items]
Goodwill	33,604
Goodwill [Roll Forward]
Net balance at June 30, 2015	33,604
Translation adjustment	0
Net balance at March 31, 2018	33,604
Storage Solutions [Member]
Goodwill [Line Items]
Goodwill	16,764
Goodwill [Roll Forward]
Net balance at June 30, 2015	16,764
Translation adjustment	78
Net balance at March 31, 2018	16,842
Industrial [Member]
Goodwill [Line Items]
Goodwill	20,981
Goodwill [Roll Forward]
Net balance at June 30, 2015	20,981
Translation adjustment	6
Net balance at March 31, 2018	$ 20,987
Houston Interests, LLC [Member]
Goodwill [Line Items]
Goodwill		$ 35,146