Net Income per Common Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Summary of Earnings Per Share Basic and Diluted

	Quarter Ended June 30,				Six Months Ended June 30,
(In millions, except per share data)	2018		2017		2018		2017
Basic net income per common share:
Net income	$	68.8	$	61.6	$	130.4	$	126.2
Weighted average common shares outstanding		88.8		90.7		89.4		91.1
Basic net income per common share	$	0.77	$	0.68	$	1.45	$	1.39
Diluted net income per common share:
Net income		68.8		61.6		130.4		126.2
Weighted average common shares outstanding — Basic		88.8		90.7		89.4		91.1
Plus incremental shares from assumed conversions:
Restricted stock units		0.4		0.4		0.4		0.4
Stock options		0.7		0.9		0.7		0.9
Weighted average common shares outstanding — Dilutive		89.9		92.0		90.5		92.4
Diluted net income per common share	$	0.76	$	0.67	$	1.44	$	1.37