Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2015

Earnings Per Share [Abstract]

Reconcilliation of Basic to Diluted Net Income Per Share

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

(in millions)	2015		2014		2013
Net income	$	95.6	$	127.1	$	112.3
Weighted average common shares outstanding	72.0		70.9		69.6
Dilutive effect of stock options, stock appreciation rights and performance share awards, based on the treasury stock method	1.8		1.9		1.7
Assumed conversion of convertible debt, based on the if-converted method	—		—		0.1
Weighted average shares assuming dilution	73.8		72.8		71.4