Net Income Per Share (Tables)

9 Months Ended

Sep. 30, 2020

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 September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Net income - basic and diluted	$	842.1	$	669.6	$	2,364.0	$	1,323.8
(Shares in millions)
Weighted average shares - basic	105.5		109.4		108.3		109.2
Effect of dilutive securities:
Stock options	7.8		4.8		7.3		5.5
Restricted stock	0.6		—		0.5		—
Weighted average shares - diluted	113.9		114.2		116.1		114.7
Net income per share - basic	$	7.98	$	6.12	$	21.83	$	12.12
Net income per share - diluted	$	7.39	$	5.86	$	20.36	$	11.54

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 September 30,		Nine Months Ended September 30,
(Shares in millions)	2020	2019	2020	2019
Stock options	0.1	18.3	2.6	18.2
Restricted stock	—	0.4	—	0.4