CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 385.0	$ 363.6	$ 300.4
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss, net of tax of $1.7, $1.4 and $1.2, respectively	3.0	2.5	1.3
Net gain (loss) arising during the period, net of tax of ($5.6), ($6.7) and $4.4, respectively	(10.2)	(13.5)	7.6
Amortization of prior service cost, net of tax of $0.2, $0.2 and $0.1, respectively	0.2	0.4	0.2
Postretirement Plans:
Amortization of deferred net loss, net of tax of ($1.1), ($1.6) and $0.6, respectively	2.0	1.8	1.2
Net loss arising during the period, net of tax of ($1.1), ($3.1) and ($2.4), respectively	(2.3)	(3.6)	(4.1)
Amortization of deferred net transition obligation, net of tax of $0.1, $0.1 and $0.1, respectively	0.1	0.2	0.1
Amortization of prior service cost, net of tax of ($1.0), ($1.6) and $0.1, respectively	(1.8)	(1.8)	0
Prior service credit arising during the period, net of tax of $0, $9.5 and $0, respectively	0	10.8	0
Deferred commodity contracts hedging (gains) losses reclassified in net income, net of tax of ($1.6), $12.6 and $9.9, respectively	(3.6)	27.6	18.5
Deferred commodity contracts hedging gains (losses), net of tax of $0.1, ($1.7) and ($8.5), respectively	0.4	(4.8)	(16.3)
Amortization of deferred interest rate swap hedging losses, net of tax of $0.2, $0.2 and $0.2, respectively	0.2	0.3	0.2
Other comprehensive income (loss), net of tax	(12.0)	19.9	8.7
Comprehensive income (loss)	373.0	383.5	309.1
Less: Comprehensive income attributable to noncontrolling interest for sale of equity investment	(0.5)	(3.2)	(6.2)
Less: Comprehensive income attributable to noncontrolling interests	27.0	24.2	5.5
Total comprehensive income attributable to OGE Energy	$ 346.5	$ 362.5	$ 309.8