Net Earnings per Share

The basic weighted average shares and common stock equivalents for the three months ended March 31, 2018 and 2017 are computed using the treasury stock method.

The following table summarizes the earnings per share attributable to FIS common stockholders for the three months ended March 31, 2018 and 2017 (in millions, except per share amounts):



	Three months ended March 31,
	2018		2017
Net earnings attributable to FIS common stockholders	$	182	$	129
Weighted average shares outstanding — basic	330		328
Plus: Common stock equivalent shares	4		5
Weighted average shares outstanding — diluted	334		333
Net earnings per share — basic attributable to FIS common stockholders	$	0.55	$	0.39
Net earnings per share — diluted attributable to FIS common stockholders	$	0.54	$	0.39

Options to purchase less than 1 million and 1 million shares of our common stock for the three months ended March 31, 2018 and 2017, respectively, were not included in the computation of diluted earnings per share because they were anti-dilutive.

On July 20, 2017 our Board of Directors approved a plan authorizing repurchases of up to $4.0 billion of our outstanding common stock in the open market at prevailing market prices or in privately negotiated transactions through December 31, 2020. This share repurchase authorization replaced any existing share repurchase authorization.