Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2016

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping [Table Text Block]

The following table summarizes the fair value and carrying amount of OG&E's financial instruments at June 30, 2016 and December 31, 2015.

	June 30, 2016				December 31, 2015
(In millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-Term Debt
Senior Notes	$	2,384.7	$	2,812.5	$	2,493.9	$	2,754.6
OG&E Industrial Authority Bonds	135.4		135.4		135.4		135.4
Tinker Debt	9.9		10.3		10.0		9.2