Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Jun. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trust assets	$ 1,011	$ 977
Money Market	38	27
U.S. Equity Securities	424	395
Foreign Equity Funds	167	185
U.S. Fixed Income Securities	219	177
Foreign Fixed Income Funds	19	57
Absolute Return Strategy Mutual Funds	144	136
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
4.26% Series A Notes	54,101	52,935
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
4.26% Series A Notes	$ 52,000	$ 53,500