Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2016

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Regulatory Assets and Liabilities [Table Text Block]

The following table is a summary of OG&E's regulatory assets and liabilities at:

(In millions)	June 30, 2016		December 31, 2015
Regulatory Assets
Current
Oklahoma demand program rider under recovery (A)	$	43.9	$	36.6
SPP cost tracker rider under recovery (A)	7.5		4.5
Other (A)	11.8		5.4
Total Current Regulatory Assets	$	63.2	$	46.5
Non-Current
Benefit obligations regulatory asset	$	237.3	$	242.2
Income taxes recoverable from customers, net	58.3		56.7
Smart Grid	43.5		43.6
Deferred storm expenses	31.8		27.6
Unamortized loss on reacquired debt	14.1		14.8
Other	16.9		17.3
Total Non-Current Regulatory Assets	$	401.9	$	402.2
Regulatory Liabilities
Current
Fuel clause over recoveries	$	41.3	$	61.3
Other (B)	4.5		7.5
Total Current Regulatory Liabilities	$	45.8	$	68.8
Non-Current
Accrued removal obligations, net	$	256.2	$	254.9
Pension tracker	26.7		17.7
Other (C)	1.0		1.0
Total Non-Current Regulatory Liabilities	$	283.9	$	273.6

(A) Included in Other Current Assets on theCondensedBalance Sheets.

(B) Included in Other Current Liabilities on theCondensedBalance Sheets.

(C) Prior year amount of$1.0 millionreclassified from deferred other liabilities to Non-Current Regulatory Liabilities.

Schedule of Change in Asset Retirement Obligation [Table Text Block]

The following table summarizes changes to OG&E's asset retirement obligations during thesix months endedJune 30, 2016and2015.

	Six Months Ended June 30,
(In millions)	2016		2015
Balance at January 1	$	63.3	$	58.6
Accretion expense	1.4		1.3
Liabilities settled	—		(0.5		)
Balance at June 30	$	64.7	$	59.4