Common Equity (Tables)

9 Months Ended

Sep. 30, 2017

Equity [Abstract]

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

Basic and diluted earnings per share for the Company were calculated as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
(In millions except per share data)	2017		2016		2017		2016
Net income	$	183.4	$	183.6	$	324.2	$	280.3
Average common shares outstanding:
Basic average common shares outstanding	199.7		199.7		199.7		199.7
Effect of dilutive securities:
Contingently issuable shares (performance and restricted stock units)	0.4		0.2		0.3		0.1
Diluted average common shares outstanding	200.1		199.9		200.0		199.8
Basic earnings per average common share	$	0.92	$	0.92	$	1.62	$	1.40
Diluted earnings per average common share	$	0.92	$	0.92	$	1.62	$	1.40
Anti-dilutive shares excluded from earnings per share calculation	—		—		—		—