Summary of Significant Accounting Policies (Details) Mcf in Thousands	12 Months Ended
	Jun. 30, 2016 USD ($) Mcf	Jun. 30, 2015 USD ($) Mcf	Jun. 30, 2014
Accounting Policies [Abstract]
Number of customers	36,000
Wholly owned subsidiaries	3
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	$ 241,833,771	$ 236,780,490
Composite depreciation rates (in hundredths)	2.80%	2.80%	2.80%
Revenue Recognition [Abstract]
Unbilled revenues	$ 1,452,000	$ 1,674,000
Unbilled gas costs	$ 319,000	$ 462,000
Unbilled Volumes (in Mcf) | Mcf	63	69
Regulatory Assets [Line Items]
The weighted average recovery period of regulatory assets not earning a return	26 years
Regulatory assets, current	$ 2,689,000	$ 2,916,000
Total other assets	18,881,126	14,917,823
Total regulatory assets	19,555,000	14,918,000
Regulatory Liabilities [Line Items]
Total regulatory liabilities	1,138,000	1,139,000
Regulatory Liability, Noncurrent	1,138,141	1,137,758
Refundable Gas Cost [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	0	1,000
Accrued cost of removal of long lived assets [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	487,000	417,000
Regulatory liability for deferred income taxes [Member]
Regulatory Liabilities [Line Items]
Total regulatory liabilities	651,000	721,000
Deferred gas costs [Member]
Regulatory Assets [Line Items]
Deferred Gas Cost	674,077	0
Conservation efficiency program expenses [Member]
Regulatory Assets [Line Items]
Total other assets	243,000	173,000
Loss on extinguishment of debt - regulatory asset [Member]
Regulatory Assets [Line Items]
Total other assets	2,689,000	2,916,000
Asset retirement obligation costs [Member]
Regulatory Assets [Line Items]
Total other assets	5,121,000	4,668,000
Accrued pension costs [Member]
Regulatory Assets [Line Items]
Total other assets	10,828,000	7,161,000
Unregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	2,607,000	2,597,000
Regulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Distribution, transmission and storage	214,660,000	210,659,000
General, miscellaneous and intangibles	23,145,000	22,785,000
Construction work in progress	1,422,000	739,000
Property, Plant and Equipment	$ 239,227,000	$ 234,183,000