Earnings per Share (Tables)

6 Months Ended

Jun. 30, 2017

Earnings Per Share [Abstract]

Schedule of Weighted Average Number of Shares

A reconciliation of basic weighted-average shares outstanding to diluted weighted-average shares outstanding is as follows:

	Three Months Ended June 30,		Six Months Ended June 30,
(in millions)	2017	2016	2017	2016
Basic weighted-average shares outstanding	156.0	164.9	157.7	166.1
Effect of dilutive securities(1)	3.0	1.8	3.2	1.7
Diluted weighted-average shares outstanding(2)	159.0	166.7	160.9	167.8

(1) The dilutive effect of outstanding stock options, restricted stock units, restricted stock, performance share units and Coworker Stock Purchase Plan units is reflected in the diluted weighted-average shares outstanding using the treasury stock method.

(2) There were less than 1 million potential common shares excluded from diluted weighted-average shares outstanding for both the three and six months ended June 30, 2017 and 2016 as their inclusion would have had an anti-dilutive effect.