Common Equity (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following table presents the calculation of basic and diluted earnings (loss) per share for OGE Energy.

(In millions except per share data)	2020		2019		2018
Net income (loss)	$	(173.7)	$	433.6	$	425.5
Average common shares outstanding:
Basic average common shares outstanding	200.1		200.1		199.7
Effect of dilutive securities:
Contingently issuable shares (performance and restricted stock units)	—		0.6		0.8
Diluted average common shares outstanding	200.1		200.7		200.5
Basic earnings (loss) per average common share	$	(0.87)	$	2.17	$	2.13
Diluted earnings (loss) per average common share	$	(0.87)	$	2.16	$	2.12
Anti-dilutive shares excluded from earnings per share calculation	0.3		—		—