Earnings Per Share

The following table sets forth the computation of basic and diluted earnings per share on net income (in thousands, except per share information):



	Three months ended March 31,
	2019		2018
Earnings:
Net income (numerator for basic and diluted calculations)	$	169,507	$	100,230
Shares:
Weighted average outstanding shares (denominator for basic calculation)	62,758		64,490
Equivalent shares from outstanding stock options	1,269		1,382
Denominator for diluted calculation	64,027		65,872
Earnings per share:
Basic	$	2.70	$	1.55
Diluted	$	2.65	$	1.52

The calculation of common equivalent shares does not include the impact of options having a strike or conversion price that exceeds the average stock price for the earnings period, as the result would be antidilutive. The calculation of common equivalent shares also excludes the impact of outstanding performance contingent shares, as the conditions necessary for their issuance have not been satisfied as of the end of the reporting period. The following table presents approximate amounts of stock options and performance contingent shares excluded from the calculation of common equivalent shares (in thousands):



	Three months ended March 31,
	2019	2018
Excluded from common equivalent shares:
Stock options	544	276
Performance contingent shares	109	212