NET INCOME (LOSS) PER SHARE

Basic net income (loss) per share is calculated by dividing the net income (loss) by the weighted-average number of shares of common stock outstanding during the period. Diluted net income (loss) per share is calculated by dividing the net income by the weighted-average number of shares of common stock outstanding during the period, plus potentially dilutive common shares, consisting of stock options and convertible debt. The Company uses the treasury-stock method to compute diluted earnings per share with respect to its stock options and equivalents. The Company uses the if-converted method to compute diluted earnings per share with respect to its convertible debt. For purposes of this calculation, options to purchase stock are considered to be potential common shares and are only included in the calculation of diluted net income (loss) per share when their effect is dilutive. Basic and diluted earnings per common share are calculated as follows:



(in thousands, except for per share amounts)	2018		2017			2016
Basic and diluted net income (loss) per share
Net income (loss)	$	36,908	$	(102,496	)	$	(88,720	)
Denominator	63,794		62,702			61,297
Basic net income (loss) per share	$	0.58	$	(1.63	)	$	(1.45	)

Diluted net income (loss) per share
Numerator:
Net income (loss)	$	36,908	$	(102,496	)	$	(88,720	)
Denominator:
Denominator for basic income (loss) per share	63,794		62,702			61,297
Add effect of diluted securities:
Stock options and equivalents	414		—			—
Denominator for diluted income (loss) per share	$	64,208	$	62,702		$	61,297
Diluted net income (loss) per share	$	0.57	$	(1.63	)	$	(1.45	)

The following table sets forth outstanding potential shares of common stock that are not included in the computation of diluted net income (loss) per share because, to do so would be anti-dilutive:



(in thousands)	2018	2017	2016
Convertible debt	17,931	17,931	17,931
Stock options and equivalents	3,701	5,618	3,371
Total potentially dilutive common shares	21,632	23,549	21,302