Earnings Per Share (Notes)

9 Months Ended

Sep. 30, 2021

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 nine months ended September 30, 2021, unvested performance-based restricted stock units and related dividend equivalent rights of 365 thousand shares were excluded from the dilutive calculation because the performance goals had not been met, with 302 thousand shares excluded for the three and nine months ended September 30, 2020.

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 September 30,		Nine Months Ended September 30,
	2021	2020	2021	2020
Weighted-average common shares outstanding—basic	89,407	89,509	89,505	89,476
Dilutive effect of potential common shares	159	—	141	153
Weighted-average common shares outstanding—diluted	89,566	89,509	89,646	89,629