Stock-Based Compensation, Phantom Stock Option Plan and Long-term Incentive Plan (Details)	3 Months Ended		9 Months Ended
	Mar. 31, 2016 USD ($) shares	Mar. 31, 2015 USD ($) shares	Mar. 31, 2016 USD ($) shares	Mar. 31, 2015 USD ($) shares	Mar. 15, 2016 shares	Dec. 31, 2015 shares	Jun. 30, 2015 USD ($)	Jun. 30, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock split ratio		2	2	2
Stock option activity, shares [Roll Forward]
Options granted (in shares)			0	0
Phantom Stock Option [Member]
Stock option activity, shares [Roll Forward]
Outstanding at beginning of year (in shares)			1,257,508	1,330,852
Options granted (in shares)			493,760	470,760
Options paid in cash upon vesting (in shares)			(396,714)	(516,744)
Outstanding at period end (in shares)	1,354,554	1,284,868	1,354,554	1,284,868
2011 Phantom Stock Option and Long-term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under the plan (in shares)					3,600,000	1,800,000		900,000
Stock option activity, shares [Roll Forward]
Cash paid on options vested | $	$ 0	$ 50,900	$ 710,500	$ 808,600
Allocated share-based compensation expense | $	290,000	$ 190,000	710,000	$ 570,000
Total liability for long-term incentive plan | $	$ 1,100,000		$ 1,100,000				$ 1,100,000
2011 Phantom Stock Option and Long-term Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Strike price of phantom stock options as percent of book value	100.00%		100.00%