Earnings Per Share (Notes)

6 Months Ended

Jun. 30, 2019

Earnings Per Share [Abstract]

Earnings per share

10. Earnings per Share 

The following is a reconciliation of the shares used to compute basic and diluted earnings per share (in millions):

	Three Months Ended		Six Months Ended
	June 30,		June 30,
	2019	2018	2019	2018
Weighted average number of common shares outstanding used to compute basic earnings per share	52.8	52.3	52.7	52.2
Dilutive effect of stock-based awards	0.6	0.7	0.6	0.7
Number of shares used to compute diluted earnings per share	53.4	53.0	53.3	52.9

During the three and six months ended June 30, 2019, there were 0.2 million and 0.3 million share equivalents outstanding that were excluded from the computation of diluted earnings per share because they were anti-dilutive when applying the treasury stock method. During the three and six months ended June 30, 2018 the amount of anti-dilutive share equivalents outstanding were insignificant.