Net Income Per Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Reconciliation of Basic to Diluted Net Income Per Share

The following table reconciles the shares used in the calculation of basic net income per share to those used for diluted net income per share:

	Three Months Ended June 30,				Six Months Ended June 30,
(in millions)	2018		2017		2018		2017
Net income	$	56.1	$	38.8	$	99.7	$	99.7
Weighted average common shares outstanding	73.6		73.9		73.8		73.6
Dilutive effect of equity awards, based on the treasury stock method	1.4		1.9		1.4		2.1
Weighted average shares assuming dilution	75.0		75.8		75.2		75.7