Earnings Per Share

6 Months Ended

Jun. 30, 2020

Earnings Per Share

Earnings Per Share

5.    Earnings Per Share

Basic and diluted earnings per share were computed using the following common share data (shares in millions):

	Three Months Ended		Six Months Ended
	June 30,		June 30,
	2020	2019	2020	2019
Number of common shares outstanding at end of period	422.2	423.8	422.2	423.8
Effect of using weighted average common shares outstanding	0.1	1.0	1.0	0.8
Weighted average basic common shares outstanding	422.3	424.8	423.2	424.6
Dilutive effect of equity-based compensation awards and other contingently issuable shares	1.6	2.7	1.9	2.6
Weighted average diluted common shares outstanding	423.9	427.5	425.1	427.2
Potentially issuable shares	6.5	7.2	6.5	7.2
Number of anti-dilutive potentially issuable shares excluded from diluted common shares outstanding	2.1	1.1	2.1	1.9