9. Earnings Per Share

Basic earnings per share is calculated by dividing income available to common shareholders by the weighted-average number of shares of common stock outstanding during each period. Diluted earnings per share (“diluted EPS”) is calculated using income available to common shareholders divided by diluted weighted-average shares of common stock outstanding during each period. Potentially dilutive securities include common shares related to SOSARs and non-vested stock awards (collectively “stock awards”). Stock awards are excluded from the calculation of diluted EPS in the event they are subject to performance conditions or are antidilutive.

The following stock awards were excluded from the calculation of diluted earnings per share:



	Three months ended March 31,
	2018		2017
Stock awards subject to performance conditions		111		241
Stock awards that were antidilutive		2,226		1,459
Total stock awards excluded from diluted earnings per share		2,337		1,700

The following table sets forth the computations of basic and diluted earnings per share:



	Three months ended March 31,
	2018		2017
Net income	$	59,446	$	46,120
Shares:
Weighted-average number of common shares outstanding		27,911		28,750
Dilutive stock awards		39		100
Diluted weighted-average number of common shares outstanding		27,950		28,850
Basic earnings per share	$	2.13	$	1.60
Diluted earnings per share	$	2.13	$	1.60