Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2021

Earnings Per Share [Abstract]

Basic and Diluted Net Income (Loss) Per Share

The calculations of basic and diluted net income per share are as follows:

	Three Months Ended March 31,
(In millions, except per share data)	2021		2020
Net income - basic and diluted	$	1,115.2	$	624.6
Weighted average shares - basic	105.4		109.8
Effect of dilutive securities:
Stock options	4.5		5.0
Restricted stock	0.6		0.3
Weighted average shares - diluted	110.5		115.1
Net income per share - basic	$	10.58	$	5.69
Net income per share - diluted	$	10.09	$	5.43

Antidilutive Securities

Shares which have been excluded from diluted per share amounts because their effect would have been antidilutive, include the following:

	Three Months Ended March 31,
(Shares in millions)	2021	2020
Stock options	5.0	10.2