REGULATION, REGULATORY FILINGS (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Mar. 31, 2012
BGSS [Member]
Schedule of Regulatory [Line Items]
Annual Recovery Amount Proposed to the Public Utility Regulatory Authority	$ (19)
Rate Increase (Decrease) Proposed to the Public Utility Regulatory Authority	(3.60%)
Customer Refunds And Bill Credits	(90.7)
EE [Member]
Schedule of Regulatory [Line Items]
Weighted Cost of Capital	7.10%
Return on Equity	10.30%
EE-Rebates and Incentives [Member]
Schedule of Regulatory [Line Items]
Recovery Amount Approved by the Board of Public Utilities	18.4
SAFE-Safety Acceleration and Facility Enhancement Program [Member]
Schedule of Regulatory [Line Items]
Originally Filed Petition for Capital Investments to the Public Utility Regulatory Authority	$ 204
Weighted Cost of Capital	7.76%
Return on Equity	10.30%