Earnings (Loss) Per Share

Basic earnings (loss) per share is calculated by dividing the net income (loss) by the weighted average number of common shares outstanding during the period. Diluted earnings (loss) per share is calculated by dividing the earnings (loss) by the weighted average number of common shares and potentially dilutive securities outstanding during the period. Potentially dilutive common shares consist of incremental common shares issuable upon exercise of stock options, employee stock purchases, restricted stock and restricted stock units and shares issuable upon the conversion of convertible notes. The dilutive effect of outstanding shares is reflected in diluted earnings (loss) per share by application of the treasury stock method. This method includes consideration of the amounts to be paid by the employees and the amount of unrecognized stock-based compensation related to future services. No potential dilutive common shares are included in the computation of any diluted per share amount when a net loss is reported.

The following table sets forth the computation of basic and diluted net income (loss) per share:



	Three Months Ended March 31,
	2018			2017
Net income (loss) per share:	(In thousands, except per share amounts)
Numerator:
Net income (loss)	$	(35,689	)	$	3,006
Denominator:
Weighted-average shares outstanding - basic	109,358			111,464
Effect of potential dilutive common shares	—			3,861
Weighted-average shares outstanding - diluted	109,358			115,325
Basic net income (loss) per share	$	(0.33	)	$	0.03
Diluted net income (loss) per share	$	(0.33	)	$	0.03

For the three months ended March 31, 2018 and 2017, options to purchase approximately 1.8 million and 2.0 million shares, respectively, were excluded from the calculation because they were anti-dilutive after considering proceeds from exercise and related unrecognized stock-based compensation expense. For the three months ended March 31, 2018, an additional 3.6 million shares have been excluded from the weighted average dilutive shares because there was a net loss position for the period.