Earnings Per Share

9 Months Ended

Sep. 30, 2019

Basic net income per share (“EPS”) is calculated by dividing net income attributable to common stockholders by the weighted average shares outstanding during the period. Diluted EPS is calculated by adjusting weighted average shares outstanding for the dilutive effect of potential common shares, determined using the treasury-stock method. For purposes of the diluted EPS calculation, stock options, restricted stock and restricted stock unit awards are considered to be potential common shares. Performance-based restricted stock units are not included in the calculation of diluted EPS until they are contingently issuable.

The basic and diluted EPS calculations for the three and nine months ended September 30, 2019 and 2018 are presented below:



	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands, except per share amounts)	2019		2018		2019		2018
Income attributable to common stockholders	$	33,597	$	35,858	$	89,646	$	91,622

Weighted average common shares outstanding, basic	66,685		67,329		66,681		67,246
Effect of dilutive securities:
Restricted stock units (a)	544		399		450		321
Stock options	132		166		109		155
Restricted stock	—		2		—		21
Weighted average common shares outstanding, diluted	67,361		67,896		67,240		67,743

Basic income per common share	$	0.50	$	0.53	$	1.34	$	1.36
Diluted income per common share	$	0.50	$	0.53	$	1.33	$	1.35

(a) Includes service-based and contingently issuable performance-based restricted stock units.

For the three and nine months ended September 30, 2019 and 2018, there were no anti-dilutive restricted stock units, stock options or restricted stock. As of September 30, 2019, the number of currently outstanding performance-based restricted stock units that are issued upon vesting could range from zero to a maximum of 0.9 million.