Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 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 March 31,
	2020		2019
Net income - basic and diluted	$	624.6	$	461.1
(Shares in millions)
Weighted average shares - basic	109.8		108.9
Effect of dilutive securities:
Stock options	5.0		6.5
Restricted stock	0.3		0.1
Weighted average shares - diluted	115.1		115.5
Net income per share - basic	$	5.69	$	4.23
Net income per share - diluted	$	5.43	$	3.99

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)	2020	2019
Stock options	10.2	12.3