Earnings Per Share (Notes)

6 Months Ended

Jun. 30, 2019

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 and six months ended June 30, 2019, unvested performance-based restricted stock units and related dividend equivalent rights of 267 thousand shares were excluded from the dilutive calculation because the performance goals had not been met, with 231 thousand shares excluded for the three and six months ended June 30, 2018.

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 June 30,		Six Months Ended June 30,
	2019	2018	2019	2018
Weighted-average common shares outstanding—basic	89,357	89,215	89,333	89,188
Dilutive effect of potential common shares	204	—	204	—
Weighted-average common shares outstanding—diluted	89,561	89,215	89,537	89,188