Acquisitions (Details Textual) - USD ($) $ in Thousands					12 Months Ended
	Feb. 01, 2016	Feb. 01, 2016	Aug. 22, 2014	Dec. 21, 2013	Jun. 30, 2016	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2015	Sep. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill					$ 78,293	$ 69,837	$ 30,836	$ 71,518
Noncontrolling interest in joint venture					(1,176)			$ (8,742)
Baillie Tank Equipment, Ltd. [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 13,049
Business Acquisition, Effective Date of Acquisition	Feb. 01, 2016
Net assets acquired	$ 13,641	13,641
Economic purchase price	15,400
Goodwill	$ 6,942	$ 6,942
Acquisition-related expenses					1,200
Revenue of Acquiree since Acquisition Date, Actual					5,400
Earnings of Acquiree since Acquisition Date, Actual					$ 300
HDB, Inc. [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition			Aug. 22, 2014
Net assets acquired			$ 5,551						$ 5,600
Tax deductible goodwill			$ 3,065
Kvaerner North American Construction [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred				$ 51,607
Stock acquired, percent				100.00%
Net assets acquired				$ 88,262						$ 88,262
Goodwill				39,295						$ 39,295
Tax deductible goodwill				30,700
Acquisition-related expenses						2,000
Incremental intangible amortization expense						4,100	4,100
Depreciation expenses						1,300	$ 1,300
Income from one-time tax settlement						$ 600
MXPB Power Partners [Member]
Business Acquisition [Line Items]
Ownership interest in joint venture, percent					65.00%
Equity of joint venture acquired				2,000
Company's portion of joint venture equity acquired				1,300
Noncontrolling interest in joint venture				$ 700