Earnings Per Share

9 Months Ended

Sep. 30, 2020

Earnings Per Share [Abstract]

Earnings Per Share

16. Earnings per Share

Basic net income (loss) per common share is computed using the two-class method, which is an earnings allocation formula that determines net income (loss) per share for each class of common stock and participating security according to dividends declared and participation rights in undistributed earnings. Under the two-class method, basic net income (loss) per common share is determined by dividing net income (loss), after deducting amounts allocated to participating securities, by the weighted average number of common shares outstanding for the period. Participating securities include unvested restricted stock and stock-settled restricted stock units that have nonforfeitable rights to receive dividends or dividend equivalents, whether paid or unpaid. During periods of net loss, only distributed earnings (dividends) are allocated to participating securities, as they do not have a contractual obligation to participate in our undistributed losses.

Diluted net income (loss) per common share is computed using the weighted average number of shares outstanding adjusted for the incremental common stock equivalents attributed to outstanding options, performance-based restricted stock units and stock to be issued pursuant to our employee stock purchase plan unless their effect would be anti-dilutive.

The following table shows the calculation for net income (loss) attributable to common stockholders, which is used in the calculation of basic and diluted net income (loss) per common share (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2020		2019		2020		2019
Income (loss) from continuing operations	$	18,332	$	20,407	$	(73,236)	$	51,559
Loss from discontinued operations, net of tax		—		—		—		(273)
Net income (loss)		18,332		20,407		(73,236)		51,286
Less: Earnings attributable to participating securities		(439)		(302)		(1,083)		(876)
Net income (loss) attributable to common stockholders	$	17,893	$	20,105	$	(74,319)	$	50,410

The following table shows the potential shares of common stock that were included in computing diluted net income (loss) per common share (in thousands):

	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2020	2019	2020	2019
Weighted average common shares outstanding including participating securities	152,973	144,692	152,790	135,081
Less: Weighted average participating securities outstanding	(1,999)	(1,761)	(2,060)	(1,911)
Weighted average common shares outstanding used in basic net income (loss) per common share	150,974	142,931	150,730	133,170
Net dilutive potential common shares issuable:
On exercise of options and vesting of performance-based restricted stock units	57	33	—	33
On settlement of employee stock purchase plan shares	7	1	—	3
Weighted average common shares outstanding used in diluted net income (loss) per common share	151,038	142,965	150,730	133,206

The following table shows the potential shares of common stock issuable that were excluded from computing diluted net income (loss) per common share as their inclusion would have been anti-dilutive (in thousands):

	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2020	2019	2020	2019
On exercise of options where exercise price is greater than average market value for the period	85	154	102	154
On exercise of options and vesting of performance-based restricted stock units	—	—	57	—
On settlement of employee stock purchase plan shares	—	—	19	—
Net dilutive potential common shares issuable	85	154	178	154