Long-Term Debt (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended					9 Months Ended						9 Months Ended	3 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Garfield Industrial Authority Bond [Member]	Sep. 30, 2014 Muskogee Industrial Authority Bond Due 2025 [Member]	Sep. 30, 2014 Muskogee Industrial Authority Bond Due 2027 [Member]	Sep. 30, 2014 Redeemable during the next 12 months	Sep. 30, 2014 Redeemable during the next 12 months Garfield Industrial Authority Bond [Member]	Sep. 30, 2014 Redeemable during the next 12 months Muskogee Industrial Authority Bond Due 2025 [Member]	Sep. 30, 2014 Redeemable during the next 12 months Muskogee Industrial Authority Bond Due 2027 [Member]	Sep. 30, 2014 OG&E [Member] Redeemable during the next 12 months Garfield Industrial Authority Bond [Member]	Sep. 30, 2014 OG&E [Member] Redeemable during the next 12 months Muskogee Industrial Authority Bond Due 2025 [Member]	Sep. 30, 2014 OG&E [Member] Redeemable during the next 12 months Muskogee Industrial Authority Bond Due 2027 [Member]	Sep. 30, 2014 Senior Notes [Member] OG&E [Member] Series due May 1, 2043 [Member]	Sep. 30, 2014 Senior Notes [Member] OG&E [Member] Series Due August 1, 2034 [Member]
Debt Instrument [Line Items]
Series Minimum						0.07%	0.08%	0.06%
Series Maximum						0.20%	0.18%	0.15%
Long term debt									$ 47.0	$ 32.4	$ 56.0	$ 250.0
Long-term debt					135.4
Debt Instrument, Interest Rate, Stated Percentage												4.55%	6.50%
Date Due		Jan. 01, 2025	Jan. 01, 2025	Jun. 01, 2027								Mar. 15, 2044	Aug. 01, 2034
Debt Instrument, Repurchased Face Amount													140.0
Percent of Principal Amount Subject to Optional Tender	100.00%
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed													103.25%
Redemption Premium													$ 4.6