Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2018

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 (in millions, except per share amounts):

	Three Months Ended March 31
	2018		2017
Numerator:
Net income	$	76.3	$	57.5
Denominator:
Weighted average shares outstanding - basic	37.9		39.4
Effect of dilutive securities:
Equity compensation plans	0.6		0.5
Weighted average shares outstanding - diluted	38.5		39.9
Basic earnings per share	$	2.02	$	1.46
Diluted earnings per share	$	1.98	$	1.44