Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trust assets	$ 1,034	$ 977
Money Market	44	27
U.S. Equity Securities	435	395
Foreign Equity Securities, Fair Value Disclosure	168	185
U.S. Fixed Income Securities	223	177
Foreign Fixed Income Security, Fair Value Disclosure	19	57
Absolute return strategy mutual funds	145	136
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
4.26% Series A Notes	55,324	52,935
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
4.26% Series A Notes	$ 51,923	$ 53,416