Earnings Per Share

3 Months Ended

Mar. 31, 2017

Earnings Per Share [Abstract]

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 March 31,
	2017			2016
Number of common shares outstanding at end of period		441.9			444.7
Effect of using weighted average common shares outstanding		(0.6	)		1.4
Weighted average basic common shares outstanding		441.3			446.1
Dilutive effect of equity-based compensation awards and other contingently issuable shares(a)		2.8			2.5
Weighted average diluted common shares outstanding		444.1			448.6
Potentially issuable shares		9.2			11.2
Number of anti-dilutive potentially issuable shares excluded from diluted common shares outstanding		3.0			2.5

(a) As of January 1, 2017, we adopted ASU 2016-09 prospectively and no longer include excess tax benefits as assumed proceeds. See Note 1 for further discussion.