Income Tax (details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
One-time, After-tax Charge	$ 2.7
Federal Statutory Tax Rate	35.00%	35.00%
Current State Income Tax, Net Of Federal Tax Benefit	4.70%	4.50%
Amortization Of Investment And Energy Tax Credits	(0.30%)	(0.40%)
Differences Required To Be Flowed Through By Regulatory Commissions	1.40%	1.50%
Gains On Company And Trust Owned Life Insurance	(1.20%)	(0.90%)
One-Time Tax Adjustment, Net of Federal Benefit	4.70%	0.00%
Other - Net	0.70%	0.70%
Effective Income Tax Rate	45.00%	40.40%