Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Average Common Shares Outstanding Basic and Diluted

The average number of common shares outstanding is reconciled to those used in the basic and diluted EPS computations as follows:

(Millions of shares)	2020	2019	2018
Basic	340.7	343.6	348.0
Dilutive effect of stock options and restricted share unit awards	1.8	2.0	1.6
Diluted	342.5	345.6	349.6