Earnings Per Share

6 Months Ended

Jun. 30, 2020

During the six months ended June 30, 2020, we repurchased 3,328,574 shares of our common stock under the repurchase program that was approved on July 30, 2019. These shares were subsequently retired. There were no shares repurchased under this program during the six months ended June 30, 2021.

The following table shows the information used in the calculation of our basic and diluted earnings per share calculation for the six months ended June 30, 2021 and 2020:


	For the Three Months Ended June 30,		For the Six Months Ended June 30,
	2021	2020	2021	2020

Weighted average common shares outstanding for basic calculation	267,560,712	267,249,580	267,440,501	268,233,233
Add: Effect of stock options, deferred share units and restricted stock units	247,232	10,815	324,877	10,764
Weighted average common shares outstanding for diluted calculation	267,807,944	267,260,395	267,765,378	268,243,997

Basic earnings per common share are calculated by dividing net income (loss) by the weighted average number of common shares outstanding, which includes 122,455 and 116,631 shares of participating securities in the three and six months ended June 30, 2021, respectively, and 65,062 and 59,166 shares of participating securities in the three and six months ended June 30, 2020, respectively. Diluted earnings per share are calculated by dividing net income (loss) by the sum of the weighted average number of common shares outstanding plus the additional common shares that would have been outstanding if potentially dilutive securities had been issued.

The weighted average common shares outstanding for the diluted earnings per share calculation excludes consideration of 1,358,696 and 1,250,722 equivalent shares in the three and six months ended June 30, 2021, respectively, and 1,734,610 and 1,603,198 in the three and six months ended June 30, 2020, respectively, as these shares are anti-dilutive.