Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2011	Sep. 30, 2010	Jun. 30, 2010
Current assets [Abstract]
Allowance for uncollectible accounts	$ 32,634	$ 41,390	$ 43,873
Regulatory assets [Abstract]
Accumulated amortization of debt issuance cost	$ 431,839	$ 397,071	$ 385,616
Common stockholders' equity [Abstract]
Par value per share of common stock (in dollars per share)	$ 5.00	$ 5.00	$ 5.00
Authorized shares of common stock (in shares)	3,500,000	3,500,000	3,500,000
Common stock shares issued and outstanding (in shares)	1,748,582	1,146,454	1,038,696