Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Computation of basic and diluted net income per common share

The following table shows the computation of our basic and diluted net income per common share for the years ending December 31 (in millions, except per share amounts):

	2019		2018		2017
Numerator:
Net income	$	211.2	$	211.3	$	502.0
Denominator:
Weighted-average shares outstanding - basic	35.7		37.6		38.8
Effect of dilutive securities:
Equity compensation plans	0.7		0.7		0.6
Weighted-average shares outstanding - diluted	36.4		38.3		39.4
Basic earnings per share	$	5.92	$	5.62	$	12.95
Diluted earnings per share	$	5.81	$	5.52	$	12.75