EARNINGS PER SHARE

Basic earnings per share are computed based on the weighted average number of common shares outstanding during the period. Diluted earnings per share are computed using the weighted average number of common shares outstanding and the effect of dilutive potential common shares outstanding during the period using the treasury stock method. Potential common shares consist of: i) employee stock purchase plan shares; and ii) contingently issuable time-based and performance-based restricted stock units, along with associated dividend equivalent rights. Unvested performance-based restricted stock units and associated dividend equivalent rights are included in dilutive potential common shares only after the performance criteria have been met.

For the three month period ended March 31, 2018, unvested performance-based restricted stock units and related dividend equivalent rights in the total amount of 230 thousand were excluded from the dilutive calculation because the performance goals had not been met, with 274 thousand excluded for the three month period ended March 31, 2017.

Net income is the same for both the basic and diluted earnings per share computations. The denominators of the basic and diluted earnings per share computations are as follows (in thousands):



	Three Months Ended March 31,
	2018	2017
Weighted-average common shares outstanding—basic and diluted	89,160	89,003