Customer Contracts (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition [Line Items]
Contract Receivable Retainage, Next Twelve Months		$ 54.3	$ 29.7
Contract Receivable Retainage, after Next Twelve Months		1.9	0.3
Retention Payable		$ 12.6	$ 14.9
Change In Accounting Estimate, Financial Effect, Operating Income	$ 53.4
Change in Accounting Estimate, Financial Effect, Net Income	18.3