Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share

Common Share Data Used for Computing Basic and Diluted Earnings Per Share

Basic and diluted earnings per share were computed using the following common share data for the years ended December 31 (shares in millions):

	2019	2018	2017
Number of common shares outstanding at end of period	424.3	424.0	433.3
Effect of using weighted average common shares outstanding	0.3	5.1	5.5
Weighted average basic common shares outstanding	424.6	429.1	438.8
Dilutive effect of equity-based compensation awards and other contingently issuable shares	2.9	3.1	3.1
Weighted average diluted common shares outstanding	427.5	432.2	441.9
Potentially issuable shares	6.7	7.4	8.1
Number of anti-dilutive potentially issuable shares excluded from diluted common shares outstanding	0.7	1.5	1.9