Net Income Per Share

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Net Income Per Share

20) Net Income Per Share

The following is a reconciliation of basic to diluted net income per share:

	Years Ended December 31,
Numerator:	2021		2020		2019
Net income	$	551.4	$	350.1	$	140.4
Denominator:
Shares used in net income per common share – basic		55.4		55.1		54.7
Effect of dilutive securities		0.3		0.2		0.4
Shares used in net income per common share – diluted		55.7		55.3		55.1
Net income per common share:
Basic	$	9.95	$	6.36	$	2.57
Diluted	$	9.90	$	6.33	$	2.55

Basic earnings per share (“EPS”) is computed by dividing income available to holders of our common stock by the weighted-average number of common shares outstanding during the period. The computation of diluted EPS is similar to the computation of basic EPS except that the denominator is increased to include the number of additional common shares that would have been outstanding (using the treasury stock method) if securities containing potentially dilutive common shares (RSUs) had been converted to such common shares, and if such assumed conversion is dilutive.

In 2021, 2020 and 2019, the potential dilutive effect of the weighted average shares of RSUs that were excluded from the computation of diluted weighted-average shares outstanding, as the shares would have had an anti-dilutive effect on EPS, were immaterial.