EARNINGS PER SHARE

Basic earnings per share is based on the weighted average number of common shares outstanding. Diluted earnings per share is based on the weighted average number of common shares outstanding, as well as dilutive common shares which include shares issuable under the equity compensation plans described in Note 12 of the consolidated financial statements. The weighted average number of diluted shares does not include potential anti-dilutive common shares aggregating 303,000, 468,000 and 653,000 at December 31, 2018, 2017 and 2016, respectively. The treasury stock method is used to calculate dilutive shares, which reduces the gross number of dilutive shares by the number of shares purchasable from the proceeds of the options assumed to be exercised and the unrecognized expense related to the options, restricted shares, restricted stock units, and performance stock units assumed to have vested.

Basic earnings and diluted weighted-average shares outstanding are as follows for the years ended December 31 (in thousands):



	2018		2017			2016
Numerator:
Income from continuing operations	$	63,809	$	62,965		$	33,719
Loss from discontinued operations	—		(405		)	(44		)
Net income available to common shareholders	$	63,809	$	62,560		$	33,675
Denominator for basic earnings per share:
Weighted average shares outstanding	31,979		31,701			31,536
Denominator for diluted earnings per share:
Common stock options and stock units	555		549			533
Weighted average shares and conversions	32,534		32,250			32,069