INCOME (LOSS) PER SHARE

12 Months Ended

Dec. 31, 2020

Basic net income (loss) per share is computed using the weighted-average number of common shares outstanding during the period. Diluted net income (loss) per share is computed using the weighted-average number of common shares and the effect of potentially dilutive securities outstanding during the period. Potentially dilutive securities include stock options, restricted stock units, performance share units, performance bonus awards, ESPP shares, warrants and convertible senior notes. If dilutive, those potentially dilutive securities are reflected in diluted net income (loss) per share using the treasury stock method, except for the convertible senior notes, which are subject to the if-converted method.

The following table sets forth the computation of basic and diluted net income (loss) per share of common stock for the years ended December 31, 2020, 2019 and 2018 (in thousands, except share amounts and per share amounts):


	Year Ended December 31,
	2020		2019		2018
Basic and diluted net income (loss) per share:
Numerator
Net income (loss) - continuing operations	$	(286,562)	$	(14,292)	$	1,988
Less: Net income (loss) attributable to noncontrolling interests	1,751		10,682		13,067
Net income (loss) attributable to common stockholders - continuing operations	$	(288,313)	$	(24,974)	$	(11,079)
Net income (loss) attributable to common stockholders - discontinued operations	382		2,597		—
Net income (loss) attributable to common stockholders	$	(287,931)	$	(22,377)	$	(11,079)
Denominator
Weighted-average common shares outstanding	28,604,115		28,370,417		28,325,555

Basic and diluted net income (loss) per share:
Continuing operations	$	(10.08)	$	(0.88)	$	(0.39)
Discontinued operations	0.01		0.09		—
Basic and diluted net income (loss) per share	$	(10.07)	$	(0.79)	$	(0.39)

The following weighted-average potentially dilutive instruments are not included in the diluted net income (loss) per share calculations above because they would have had an antidilutive effect on the net income (loss) per share from continuing operations:


	Year Ended December 31,
	2020	2019	2018
Restricted stock units	1,887,322	1,652,002	1,527,601
Other stock-based compensation awards	199,629	125,562	102,054
Convertible senior notes	2,314,815	2,314,815	2,314,815
Warrants	2,314,815	2,314,815	2,314,815
Total	6,716,581	6,407,194	6,259,285

We had outstanding Market-based Performance Share Units as of December 31, 2020 that were eligible to vest into shares of common stock subject to the achievement of specified performance or market conditions. Contingently issuable shares are excluded from the computation of diluted earnings per share if, based on current period results, the shares would not be issuable if the end of the reporting period were the end of the contingency period. As of December 31, 2020, there were up to 57,668 shares of common stock issuable upon vesting of outstanding Market-based Performance Share Units that were excluded from the table above as the performance or market conditions were not satisfied as of the end of the period.