Short-Term Debt and Credit Facility Short-Term Debt and Credit Facility (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013
Line of Credit Facility [Line Items]
Advances from parent	$ 87.2	$ 0
Advances to parent	0	90.3
OG&E [Member]
Line of Credit Facility [Line Items]
Intercomany Borrowings, Maximum Borrowing Capacity	400.0
Intercompany Borrowing Agreement, Expiration Date		Dec. 13, 2017
Outstanding Intercompany Borrowings			0
Line of Credit Facility, Maximum Borrowing Capacity	400.0
Letters of Credit Outstanding, Amount	2.1
Short-term Debt, Weighted Average Interest Rate	0.53%
Line of Credit Facility, Amount Outstanding	0
Commercial Paper	0
Period For Which Regulatory Approval Has Been Given to Acquire Short Term Debt	2 years
Short Term Borrowing Capacity That Has Regulatory Approval	800
Maximum [Member]
Line of Credit Facility [Line Items]
Cash	$ 0.1