Earnings Per Share

3 Months Ended

Mar. 31, 2019

12. Earnings Per Share

Basic net income per share is calculated by dividing the net income attributable to common shares by the weighted-average number of common shares outstanding during the period. Diluted net income per share adjusts basic net income per share for the effects of potentially dilutive common shares, if the effect is not antidilutive. Potentially dilutive common stock consists of shares issuable under the 2010 Plan.

The following is a summary of basic and diluted net income per share (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2019		2018
Net income attributable to common shares	$	19,661	$	20,302
Weighted-average common shares outstanding - basic		36,347,781		33,935,564
Effect of potentially dilutive common shares:
Stock options		38,921		53,813
Unvested awards		160,363		174,858
Weighted-average common shares outstanding - diluted		36,547,065		34,164,235
Net income per share attributable to common shares
Basic	$	0.54	$	0.60
Diluted	$	0.54	$	0.59

In the calculations above, we have excluded weighted-average potentially dilutive securities of 39,754 and 37,760 for the three months ended March 31, 2019, and 2018, respectively, as their effect would have been antidilutive.