Earnings Per Common Share

9 Months Ended

Sep. 30, 2020

Earnings Per Common Share [Abstract]

Basic earnings per common share (EPS) is computed by dividing net income by the weighted-average number of shares of common stock outstanding. For purposes of calculating diluted EPS, the denominator reflects the potential dilution that could occur if stock options, unvested restricted stock units or other contracts to issue common stock were exercised or converted into common stock, using the treasury stock method.

The following table summarizes the calculation of basic and diluted EPS for the three and nine months ended September 30, 2020 and 2019:


	Three months ended				Nine months ended
	September 30,				September 30,
	2020		2019		2020		2019
Net income used for basic and diluted calculation	$	578.1	$	467.6	$	67.6	$	1,515.3
Shares used in computing earnings per common share—basic	219.1		223.3		220.4		223.8
Weighted-average effect of dilutive securities:
Stock awards	1.5		1.2		1.5		1.6
Shares used in computing earnings per common share—diluted	220.6		224.5		221.9		225.4
Earnings per common share:
Basic	$	2.64	$	2.09	$	0.31	$	6.77
Diluted	$	2.62	$	2.08	$	0.30	$	6.72

We exclude from diluted EPS the weighted-average number of securities whose effect is anti-dilutive. Excluded from the calculation of EPS for the three and nine months ended September 30, 2020 were 2.5 and 1.8 shares of common stock, respectively, because their effect is anti-dilutive. Excluded from the calculation of EPS for the three and nine months ended September 30, 2019 were 3.3 and 3.1 shares of common stock, respectively, because their effect is anti-dilutive.