Capitalization (Narrative) (Details) (USD $) Share data in Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Dec. 31, 2014	Oct. 31, 2014
Schedule of Capitalization [Line Items]
Issuance of shares under the DRP,shares	16,172	18,919
Issuance of shares under the DRP	$ 400,000	$ 400,000
Proceeds from long-term debt borrowing	3,000,000	211,000
Other long term debt	53,200,000		53,200,000	50,800,000
Customer advances	21,927,000		21,927,000	21,978,000
New Jersey Environmental Infrastructure Trust [Member]
Schedule of Capitalization [Line Items]
Loan amount				5,000,000
Tidewater [Member]
Schedule of Capitalization [Line Items]
Loan amount	4,000,000		4,000,000		15,000,000
Proceeds from long-term debt borrowing	$ 3,000,000		$ 11,000,000
Interest rate	4.46%		4.46%
Due date of debt	Apr. 01, 2040