Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2017

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)	March 31, 2017		December 31, 2016
Regulatory Assets
Current
Fuel clause under recoveries	$	73.4	$	51.3
Oklahoma demand program rider under recovery (A)	45.6		51.0
SPP cost tracker under recovery (A)	14.6		10.0
Other (A)	8.6		9.5
Total Current Regulatory Assets	$	142.2	$	121.8
Non-Current
Benefit obligations regulatory asset	$	228.9	$	232.6
Income taxes recoverable from customers, net	65.6		62.3
Deferred storm expenses	40.5		35.7
Smart Grid	38.2		43.2
Unamortized loss on reacquired debt	13.1		13.4
Other	16.8		17.6
Total Non-Current Regulatory Assets	$	403.1	$	404.8
Regulatory Liabilities
Current
Other (B)	$	13.4	$	12.3
Total Current Regulatory Liabilities	$	13.4	$	12.3
Non-Current
Accrued removal obligations, net	$	268.6	$	262.8
Pension tracker	36.6		35.5
Other	1.5		1.4
Total Non-Current Regulatory Liabilities	$	306.7	$	299.7

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

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

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

The following table summarizes changes to OG&E's asset retirement obligations during thethree months endedMarch 31, 2017and2016.

	Three Months Ended March 31,
(In millions)	2017		2016
Balance at January 1	$	69.6	$	63.3
Accretion expense	0.7		0.7
Balance at March 31	$	70.3	$	64.0