Summary of Significant Accounting Policies Depreciation and Amortization (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Provision for Depreciation Rate	2.80%	3.00%
Projected provision for depreciation in next fiscal year	2.80%
Percent Of Intangible Plant Balance Amortizable	93.50%
Percent of Intangible Plant Balance Amortizable Thereafter	6.50%
Transmission Equipment [Member] | OG&E [Member]
Amount of Acquisition Adjustments	$ 3.3	$ 3.3