Earnings Per Share

12 Months Ended

Dec. 31, 2017

8. Earnings Per Share

Earnings per share is computed in accordance with ASC 260, Earnings per Share. Basic earnings per share is computed on the basis of weighted average outstanding common shares. Diluted earnings per share is computed on the basis of basic weighted average outstanding common shares adjusted for the dilutive effect of stock options and other outstanding dilutive securities.

The following table reconciles the average share amounts used to compute both basic and diluted earnings per share (in thousands):


	Years Ended December 31,
	2017		2016		2015
Weighted average shares outstanding:
Basic weighted average shares outstanding		118,059		117,533		117,465
Add: Dilutive effect of stock options		1,385		1,314		1,454

Diluted weighted average shares outstanding		119,444		118,847		118,919

For the years ended December 31, 2017, 2016, and 2015, respectively, 3.9 million, 6.1 million, and 3.7 million, options to purchase shares and contingently issuable shares, were excluded from the diluted earnings per share computation as their effect would be anti-dilutive.

Common stock outstanding as of December 31, 2017 and 2016 was 117,096,731 and 117,336,797, respectively.