Earnings Per Share

12 Months Ended

Dec. 31, 2020

Basic earnings per common share is computed by dividing net income available to common stockholders by the weighted average of common shares outstanding during the period. Diluted earnings per common share adjusts basic earnings per common share for the effects of stock options and restricted stock in the periods where such items are dilutive.

On July 24, 2019, the Board of Directors approved an up to $400 million share repurchase program to be executed over the two-year period ending July 2021, which was completed in November 2020. On October 28, 2020, a new authorization of $500 million was put into place through December 2023. During 2020, the total repurchases were 3,338,028 common shares for $399.6 million,or $119.70 per share. The number repurchased in 2020 under the July 2019 authorization were 2,368,374 common shares for $274.6 million, or $115.93 per share and shares purchased under the October 2020 authorization were 969,654 common shares for $125.0 million, or $128.91 per share, leaving approximately $375.0 million, at December 31, 2020, available until December 2023.

During 2019, the total number of common shares repurchased were 1,898,023 for $165.8 million, or $87.35 per share, of which 1,393,626 common shares were under the July 2019 plan for $125.0 million, or $89.70 per share and other shares purchased were 504,397 common shares for $40.8 million, or $80.85 per share. During 2018 the Company acquired 1,994,632 common shares at an average price of $72.39.

The following table provides a reconciliation of basic and diluted earnings per share computations for the years ended December 31, 2020, 2019 and 2018 (in millions, except per share amounts):


	Years ended December 31,
(Millions of dollars except per share amounts)	2020		2019		2018
Earnings per common share:
Net income per share - basic


Net income attributable to common stockholders	$	386.1	$	154.8	$	213.6

Weighted average common shares outstanding (in thousands)	29,132		31,594		32,674



Earnings per common share	$	13.25	$	4.90	$	6.54

Earnings per common share - assuming dilution:

Net income per share - diluted


Net income attributable to common stockholders	$	386.1	$	154.8	$	213.6
Weighted average common shares outstanding (in thousands)	29,132		31,594		32,674
Common equivalent shares:
Share-based awards	394		264		309
Weighted average common shares outstanding - assuming dilution (in thousands)	29,526		31,858		32,983




Earnings per common share assuming dilution	$	13.08	$	4.86	$	6.48

We have excluded from the earnings-per-share calculation certain stock options and shares that are considered to be anti-dilutive under the treasury stock method and are reported in the table below.


	Years ended December 31,
Potentially dilutive shares excluded from the calculation as their inclusion would be anti-dilutive	2020	2019	2018
Stock options	75,600	94,600	76,400
Restricted share units	20,137	843	121
Total anti-dilutive shares	95,737	95,443	76,521