Earnings per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following is a reconciliation of the number of shares and share equivalents used to calculate basic and diluted earnings per share (in millions, except per share amounts):

	Year Ended December 31,
	2020		2019		2018
Net income	$	200.3	$	174.7	$	157.7
Weighted-average number of common shares outstanding - basic	52.7		52.8		52.3
Dilutive effect of share equivalents	0.6		0.6		0.8
Number of common shares and share equivalents outstanding - diluted	53.3		53.4		53.1
Basic earnings per share	$	3.80	$	3.31	$	3.02
Diluted earnings per share	$	3.76	$	3.28	$	2.98
Number of anti-dilutive share equivalents	—		—		—