11. 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 June 30,				Six months ended June 30,
	2018		2017		2018		2017
Stock awards subject to performance conditions		108		247		100		244
Stock awards that were antidilutive		2,061		1,506		2,144		1,482
Total stock awards excluded from diluted earnings per share		2,169		1,753		2,244		1,726

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



	Three months ended June 30,				Six months ended June 30,
	2018		2017		2018		2017
Net income	$	46,884	$	66,730	$	106,330	$	112,850
Shares:
Weighted-average number of common shares outstanding		27,819		28,649		27,865		28,699
Dilutive stock awards		116		151		77		126
Diluted weighted-average number of common shares outstanding		27,935		28,800		27,942		28,825
Basic earnings per share	$	1.69	$	2.33	$	3.82	$	3.93
Diluted earnings per share	$	1.68	$	2.32	$	3.81	$	3.92