Employee Stock Ownership Plan - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Initial term of employer loan		15 years
Employer loan, annual interest rate	3.80%
Compensation Expense	$ 2.3	$ 2.5	$ 3.4
Difference between cost and market value of committed to be released shares	$ 0.1	$ 0.5	$ 0.0