Net Income per Common Share (Tables)

9 Months Ended

Sep. 30, 2015

Earnings Per Share [Abstract]

Summary of Earnings Per Share Basic and Diluted

	Quarter Ended September 30,				Nine Months Ended September 30,
(In millions, except per share data)	2015		2014		2015		2014
Basic net income per common share:
Net income	$	53.5	$	55.8	$	183.3	$	156.5
Weighted average common shares outstanding		95.8		95.8		96.2		97.2
Basic net income per common share	$	0.56	$	0.58	$	1.91	$	1.61
Diluted net income per common share:
Net income	$	53.5	$	55.8	$	183.3	$	156.5
Weighted average common shares outstanding — Basic		95.8		95.8		96.2		97.2
Plus incremental shares from assumed conversions:
Restricted stock units		0.5		0.7		0.5		0.8
Stock options		1.0		1.2		1.0		1.2
Weighted average common shares outstanding — Dilutive		97.3		97.7		97.7		99.2
Dilutive net income per common share	$	0.55	$	0.57	$	1.88	$	1.58