Earnings Per Share

The Company reports basic and diluted earnings per share. Basic earnings per share is computed by dividing net income attributable to shareholders of the Company by the weighted average number of common shares outstanding during the reported period. Diluted earnings per share reflect the potential dilution related to equity-based incentives using the treasury stock method. The calculation and reconciliation of basic and diluted earnings per share for the three and six month periods ended June 30 follows (in thousands, except per share data):



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Net income	$	176,852	$	130,987	$	351,789	$	254,680
Denominator for basic earnings per share	89,169		92,013		89,466		92,060
Dilutive securities	3,533		2,210		3,504		2,332
Denominator for diluted earnings per share	92,702		94,223		92,970		94,392
Basic earnings per share	$	1.98	$	1.42	$	3.93	$	2.77
Diluted earnings per share	$	1.91	$	1.39	$	3.78	$	2.70

Diluted earnings per share for the three months ended June 30, 2018 and 2017 excludes the effect of 0.1 million and 3.7 million shares of common stock, respectively, that may be issued upon the exercise of employee stock options because such effect would be anti-dilutive. Diluted earnings per share also excludes the effect of 0.1 million and 0.2 million shares of performance based restricted stock for which the performance criteria have not yet been achieved for the three month periods ended June 30, 2018 and 2017, respectively.