Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2019

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:

	Year Ended December 31,
	2019	2018	2017
Basic weighted-average shares outstanding	145.1	150.9	155.4
Effect of dilutive securities (1)	2.7	2.7	2.8
Diluted weighted-average shares outstanding (2)	147.8	153.6	158.2

(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 fewer than 0.1 million potential common shares excluded from diluted weighted-average shares outstanding for the years ended December 31, 2019, 2018 and 2017, respectively, as their inclusion would have had an anti-dilutive effect.