Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

Operating Lease Obligations

OG&E has operating lease obligations expiring at various dates, primarily forrailcar leases and wind farm land leases. Future minimum payments for noncancellable operating leasesare as follows:

Year ended December 31 (In millions)	2013		2014		2015		2016		2017		After 2017		Total
Operating lease obligations
Railcars	$	3.2	$	2.8	$	2.7	$	27.3	$	—	$	—	$	36.0
Wind farm land leases	2.0		2.1		2.1		2.1		2.4		51.2		61.9
Total operating lease obligations	$	5.2	$	4.9	$	4.8	$	29.4	$	2.4	$	51.2	$	97.9

Unrecorded Unconditional Purchase Obligations Disclosure [Table Text Block]

Other Purchase Obligations and Commitments

OG&E's other future purchase obligations and commitments estimated for the next five years are as follows:

(In millions)	2013		2014		2015		2016		2017		Total
Other purchase obligations and commitments
Cogeneration capacity and fixed operation and maintenance payments	$	87.9	$	85.8	$	84.5	$	82.4	$	80.1	$	420.7
Expected cogeneration energy payments	58.6		63.8		70.5		81.0		87.3		361.2
Minimum fuel purchase commitments	452.5		535.6		—		—		—		988.1
Expected wind purchase commitments	57.5		58.0		58.9		59.8		60.8		295.0
Long-term service agreement commitments	8.0		27.8		6.7		6.2		6.4		55.1
Total other purchase obligations and commitments	$	664.5	$	771.0	$	220.6	$	229.4	$	234.6	$	2,120.1

Schedule of Wind Power Purchases [Table Text Block]

The following table summarizes OG&E's wind power purchases for the years endedDecember 31, 2012, 2011and2010. 

Year ended December 31 (In millions)	2012		2011		2010
CPV Keenan	$	25.1	$	24.5	$	3.8
Edison Mission Energy	20.2		8.5		—
FPL Energy	3.4		3.7		3.9
NextEra Energy	0.8		—		—
Total wind power purchased	$	49.5	$	36.7	$	7.7