Earnings Per Share

6 Months Ended

Jun. 30, 2016

Earnings Per Share [Abstract]

Earnings Per Share

6. Earnings Per Share

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

	Three Months Ended June  30,				Six Months Ended June  30,
	2016		2015		2016		2015
Number of common shares outstanding at end of period		441.7		451.8		441.7		451.8
Effect of using weighted average common shares outstanding		2.3		3.7		3.3		5.2
Weighted average basic common shares outstanding		444.0		455.5		445.0		457.0
Dilutive effect of equity-based compensation awards and other contingently issuable shares		2.7		2.5		2.5		2.6
Weighted average diluted common shares outstanding		446.7		458.0		447.5		459.6
Potentially issuable shares		10.1		11.2		10.1		11.2
Number of anti-dilutive potentially issuable shares excluded from diluted common shares outstanding		0.5		2.3		0.8		2.3