Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2018

Earnings Per Share [Abstract]

Computations of Basic and Diluted Earnings per Share

The weighted average number of common shares used in the calculation of basic and diluted earnings per share consisted of the following (in millions):

	Third Quarter		Nine Months
	2018	2017	2018	2017
Weighted average basic common shares outstanding	35.9	35.3	35.7	35.2
Effect of dilutive securities (primarily stock options)	1.3	1.1	1.3	1.0
Weighted average diluted common shares outstanding	37.2	36.4	37.0	36.2