Earnings Per Share Data

6 Months Ended

Jun. 30, 2017

Basic earnings per common share is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted earnings per share adjusts basic earnings per common share for the effects of potentially dilutive common shares, if the effect is not anti-dilutive. Potentially dilutive common shares include the dilutive effects of shares issuable under the stock option and performance award plans.

The following table reconciles the basic earnings per share computation to the diluted earnings per share computation (in millions, except share and per share amounts):



	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
Net income available to common stockholders for purposes of computing basic and diluted earnings per share	$	134.4	$	120.1	$	280.9	$	227.8
Weighted-average number of shares outstanding (in thousands):
Basic shares	105,473		107,720		105,792		107,891
Effect of dilution	285		187		250		203
Diluted shares	105,758		107,907		106,042		108,094
Earnings per share:
Basic earnings per share	$	1.27	$	1.12	$	2.66	$	2.11
Diluted earnings per share	$	1.27	$	1.11	$	2.65	$	2.11

Potentially dilutive shares excluded from the calculation (in thousands):



Stock options excluded as their inclusion would be anti-dilutive	111	48	210	185