(11) Earnings Per Share

Basic earnings per share is computed by dividing the net income available to common stockholders by the weighted average number of shares of common stock outstanding. For purposes of calculating diluted earnings per share, the denominator includes both the weighted average number of shares of common stock outstanding and the number of dilutive common stock equivalents such as stock options and restricted stock units.

Stock options and restricted stock units of 239,020 and 12,256 for the three months ended March 31, 2018 and March 31, 2017, respectively, and stock options and restricted stock units of 125,995 and 415,038 for the nine months ended March 31, 2018 and March 31, 2017, respectively, were not included in the computation of diluted earnings per share as the effect would have been anti-dilutive.

Basic and diluted earnings per share for the three and nine months ended March 31, 2018 and March 31, 2017 are calculated as follows (in thousands except per share data):


	Three Months Ended March 31,				Nine Months Ended March 31,
	2018		2017		2018		2017
Numerator:
Net income	$	110,125	$	87,823	$	205,777	$	240,672
Denominator:
Basic weighted-average common shares outstanding		142,898		141,714		142,688		141,266
Effect of dilutive securities:
Stock options and restricted stock units		1,087		1,010		1,207		1,097
Diluted weighted average shares		143,985		142,724		143,895		142,363
Basic earnings per share	$	0.77	$	0.62	$	1.44	$	1.70
Diluted earnings per share	$	0.76	$	0.62	$	1.43	$	1.69