Retirement Plans - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Employer matching contributions (as a percent)	50.00%
Maximum employee's pretax contribution that can be matched (as a percent)	6.00%
Employer matching contributions	$ 2.5	$ 2.4	$ 2.2

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration