Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2011	Sep. 30, 2010	Jun. 30, 2010
Plant [Abstract]
Utility property, plant and equipment	$ 46,301,020	$ 43,785,340	$ 42,477,222
Less: accumulated depreciation	(14,061,321)	(13,037,075)	(13,013,295)
Total plant utility and non-utility, net	32,239,699	30,748,265	29,463,927
Investments [Abstract]
Marketable securities available-for-sale at fair value	2,402,992	2,366,870	2,213,203
Current assets [Abstract]
Cash and cash equivalents	161,107	69,552	214,913
Customer accounts receivable, (net of allowance for uncollectible accounts of $32,634, $43,873 and $41,390)	1,983,706	1,251,584	1,489,316
Gas stored underground, at average cost	1,906,831	2,696,395	1,538,872
Materials and supplies inventory	726,569	774,677	814,683
Deferred income taxes	216,380	0	0
Prepaid expenses	284,561	967,038	1,048,183
Total current assets	5,279,154	5,759,246	5,105,967
Regulatory assets [Abstract]
Unrecovered gas costs	17,150	1,093,029	746,174
Deferred regulatory costs	1,035,836	1,052,427	1,123,230
Unamortized debt issuance cost (net of accumulated amortization of $431,839, $385,616 and $397,071)	281,753	303,468	289,280
Deferred income taxes	0	0	77,484
Other	232,074	168,334	142,851
Total deferred debits and other assets	1,566,813	2,617,258	2,379,019
Total assets	41,488,658	41,491,639	39,162,116
Current liabilities [Abstract]
Current portion of long-term debt	1,145,269	971,417	978,747
Demand notes payable	750,000	1,250,000	500,000
Borrowings under lines-of-credit	2,358,958	5,140,649	4,667,490
Accounts payable	1,702,540	1,367,884	1,646,994
Accrued expenses	681,069	842,935	912,386
Customer deposits and accrued interest	589,206	1,083,068	717,973
Dividends declared	200,869	171,683	155,519
Deferred income taxes	0	359,254	96,227
Total current liabilities	7,427,911	11,186,890	9,675,336
Long-term debt, less current installments	9,807,519	8,656,394	9,121,022
Deferred credits and other liabilities [Abstract]
Deferred income taxes	733,955	31,035	0
Deferred compensation	1,850,111	1,938,106	1,999,406
Deferred pension costs & post-retirement benefits	6,855,493	5,823,219	6,984,087
Other	167,201	179,198	111,265
Total deferred credits and other liabilities	9,606,760	7,971,558	9,094,758
Common stockholders' equity [Abstract]
Common stock (common stock $5.00 par value per share. Authorized 3,500,000 shares; issued and outstanding 1,748,582 shares at June 30, 2011, 1,038,696 shares at June 30, 2010 and 1,146,454 at September 30, 2010)	8,742,910	5,732,270	5,193,480
Other paid-in capital	7,065,322	8,130,264	6,696,159
Retained earnings	1,484,905	2,054,115	2,435,635
Accumulated other comprehensive loss	(2,646,669)	(2,239,852)	(3,054,274)
Total common stockholders' equity	14,646,468	13,676,797	11,271,000
Total liabilities and capitalization	$ 41,488,658	$ 41,491,639	$ 39,162,116