Earnings Per Share

Diluted weighted average shares is calculated as basic weighted average shares plus the effect, calculated using the treasury stock method, of assuming that restricted share units, performance share units and purchase match units have vested. The following table provides the weighted average number of common shares outstanding used in the calculation of the Company's basic and diluted earnings per share for the years ended December 31, 2017, 2016 and 2015:



(In thousands, except per share data)	Year Ended December 31
(In thousands, except per share data)	2017			2016			2015
Weighted average number of common shares outstanding, basic	53,393			53,216			54,795
Dilutive effect of securities:
Restricted Share Units	85			73			52
Performance Share Units	110			135			145
Purchase Match Units	23			24			25
Weighted average number of common shares outstanding, diluted	53,611			53,448			55,017
Effect of dilutive shares on earnings per share	$	(0.01	)	$	(0.01	)	$	(0.01	)

All dilutive common share equivalents are reflected in the earnings per share calculation while antidilutive common share equivalents are not reflected in the earnings per share calculation. The diluted weighted average number of common shares outstanding for the year ended December 31, 2017 excludes approximately 7,000 common share equivalents issuable under the Company's stock compensation plans, as their effect would be antidilutive. There were no common share equivalents that were antidilutive for the years ended December 31, 2016 and 2015.