Consolidated Statements of Income - USD ($)	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Operating Revenues
Total operating revenues	$ 64,130,220	$ 86,188,238	$ 95,845,871
Operating Expenses
Operation and maintenance	13,989,510	14,608,835	15,495,537
Depreciation and amortization	6,416,221	6,377,743	6,147,618
Taxes other than income taxes	2,965,250	2,795,609	2,324,426
Total operating expenses	52,696,228	73,224,377	80,242,432
Operating Income	11,433,992	12,963,861	15,603,439
Other Income (Expense), Net	4,124	25,097	201,462
Interest Charges
Interest on long-term debt	2,245,224	2,309,124	2,373,024
Other interest expense	52,533	51,538	51,563
Amortization of debt expense	233,500	240,000	246,600
Total interest charges	2,531,257	2,600,662	2,671,187
Net Income Before Income Taxes	8,906,859	10,388,296	13,133,714
Income Tax Expense	3,377,481	3,892,215	4,858,586
Net Income	$ 5,529,378	$ 6,496,081	$ 8,275,128
Earnings Per Common Share (Note 11)
Basic (in dollars per share)	$ 0.78	$ 0.92	$ 1.19
Diluted (in dollars per share)	0.78	0.92	1.19
Dividends Declared Per Common Share (in dollars per share)	$ 0.82	$ 0.80	$ 0.76
Regulated Operation [Member]
Operating Revenues
Regulated revenues	$ 41,242,094	$ 52,681,120	$ 57,054,180
Operating Expenses
Regulated Purchased gas	11,704,178	22,728,766	27,215,425
Other Income (Expense), Net	4,000	25,000	183,000
Interest Charges
Total interest charges	2,486,000	2,551,000	2,633,000
Income Tax Expense	3,238,000	3,553,000	3,907,000
Net Income	4,982,000	5,748,000	6,407,000
Unregulated Operation [Member]
Operating Revenues
Non-regulated revenues	22,888,126	33,507,118	38,791,691
Operating Expenses
Non-regulated purchase gas	17,621,069	26,713,424	29,059,426
Other Income (Expense), Net	0	0	18,000
Interest Charges
Total interest charges	45,000	50,000	38,000
Income Tax Expense	139,000	339,000	952,000
Net Income	$ 547,000	$ 748,000	$ 1,868,000