Income Taxes (Details) - USD ($)	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Unrecognized Tax Positions [Line Items]
Unrecognized Tax Benefits	$ 5,000	$ 64,000
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	(5,000)	(59,000)
Unrecognized Tax Benefits	0	5,000	$ 64,000
Deferred Tax Liabilities [Abstract]
Deferred gas costs	(256,000)	0
Prepaid expenses	(392,000)	(452,000)
Accelerated depreciation	(38,862,000)	(38,108,000)
Other	(1,084,000)	(1,119,000)
Pensions	0	(805,000)
Regulatory assets - asset retirement obligation	(981,000)	(876,000)
Regulatory assets - loss on extinguishment of debt	(1,021,000)	(1,107,000)
Regulatory assets - unrecognized accrued pension	(4,110,000)	(2,718,000)
Deferred Tax Liabilities Regulatory Liabilities	(837,000)	(1,268,000)
Total	(47,543,000)	(46,453,000)
Deferred Tax Assets [Abstract]
Accrued employee benefits	875,000	1,131,000
Asset retirement obligations	1,425,000	1,378,000
Investment tax credits	0	7,000
Other	92,000	105,000
Regulatory liabilities	1,084,000	1,540,000
Bad debt reserve	114,000	98,000
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions	516,000	0
Section 263(a) capitalized costs	32,000	64,000
Deferred Tax Assets Current and NonCurrent, Total	4,138,000	4,323,000
Net accumulated deferred income tax liability	(43,405,000)	(42,130,000)
Current
Federal	1,817,036	1,949,328	4,531,805
State	366,622	493,416	842,271
Total	2,183,658	2,442,744	5,374,076
Deferred	1,193,823	1,449,471	(515,490)
Income tax expense	$ 3,377,481	$ 3,892,215	$ 4,858,586
Effective Income Tax Rate Reconciliation [Abstract]
Statutory federal income tax rate (in hundredths)	34.00%	34.00%	34.00%
State income taxes, net of federal benefit (in hundredths)	4.00%	4.00%	4.00%
Amortization of investment tax credits (in hundredths)	(0.10%)	(0.10%)	(0.10%)
Other differences, net (in hundredths)	0.00%	(0.40%)	(0.90%)
Effective income tax rate (in hundredths)	37.90%	37.50%	37.00%
Unrecognized tax benefits, interest accrued	$ 0
Unrecognized tax benefits, interest recognized		$ 0