Fair Value Measurements Carrying and Fair Value Amounts (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	$ 2,400.1	$ 2,848.6
OG&E Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	2,154.5	1,904.2
Long-Term Debt, Fair Value	2,405.0	2,401.6
OG&E Industrial Authority Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	135.4	135.4
Long-Term Debt, Fair Value	135.4	135.4
OG&E Tinker Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	10.3	10.7
Long-Term Debt, Fair Value	9.1	10.0
OGE Energy Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	99.9	99.9
Long-Term Debt, Fair Value	103.1	106.3
Enogex LLC Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt		448.4	[1]
Long-Term Debt, Fair Value		493.4	[1]
Enogex LLC Term Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt		250.0	[1]
Long-Term Debt, Fair Value		250.0	[1]
Long-term Debt [Member] | OG&E [Member] | Due August 31, 2062 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt, gross	$ 10.3	$ 10.7

[1] As a result of the formation of Enable on May 1, 2013 and the Company's deconsolidation of Enogex Holdings, the Company's consolidated financial statements do not include any obligations for the Enogex LLC Senior Notes and Enogex LLC Term Loan as of May 1, 2013.