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 years ended December 31 (in thousands, except per share data) follows:



	2017		2016		2015
Net income	$	740,200	$	452,385	$	362,431
Denominator for basic earnings per share	91,129		92,597		92,023
Dilutive securities	2,465		2,616		2,116
Denominator for diluted earnings per share	93,594		95,213		94,139
Basic earnings per share	$	8.12	$	4.89	$	3.94
Diluted earnings per share	7.91		4.75		3.85

There were 0.1 million antidilutive shares for the year ended December 31, 2017. Diluted earnings per share for the years ended December 31, 2017, 2016 and 2015 excludes the effect of 0.1 million , 0.4 million and 1.4 million shares, respectively, of common stock that may be issued upon the exercise of employee stock options because such effect would be antidilutive. There were 0.1 million antidilutive shares for 2016. Diluted earnings per share also excludes the effect of 0.3 million, 0.2 million and 0.2 million shares of performance based restricted stock for which the performance criteria have not yet been achieved for the years ended December 31, 2017, 2016 and 2015, respectively.