Income Taxes (Narrative) (Details) (USD $)	Dec. 31, 2012	Sep. 30, 2012
Income Taxes [Line Items]
Taxes refundable to customers	$ 66,396,000	$ 66,392,000
Recoverable future taxes	152,202,000	150,941,000
Tax Benefit Not Realized Due to Tax Loss Carryforward	37,500,000	32,700,000
Deferred Income Taxes [Member]
Income Taxes [Line Items]
Taxes refundable to customers	66,400,000	66,400,000
Recoverable future taxes	$ 152,200,000	$ 150,900,000