Intangible Assets Including Goodwill - Carrying Value of Goodwill By Segment (Details) $ in Thousands	9 Months Ended
	Mar. 31, 2021 USD ($)
Goodwill [Line Items]
Goodwill	$ 60,369
Goodwill [Roll Forward]
Net balance at June 30, 2020	60,369
Translation adjustment	236
Net balance at March 31, 2021	60,605
Utility and Power Infrastructure [Member]
Goodwill [Line Items]
Goodwill	6,975
Goodwill [Roll Forward]
Net balance at June 30, 2020	6,905
Translation adjustment	70
Net balance at March 31, 2021	6,975
Process and Industrial Facilities
Goodwill [Line Items]
Goodwill	26,873
Goodwill [Roll Forward]
Net balance at June 30, 2020	26,846
Translation adjustment	27
Net balance at March 31, 2021	26,873
Storage and Terminal Solutions
Goodwill [Line Items]
Goodwill	26,757
Goodwill [Roll Forward]
Net balance at June 30, 2020	26,618
Translation adjustment	139
Net balance at March 31, 2021	$ 26,757