SHAREHOLDERS' EQUITY (Tables)

12 Months Ended

Dec. 31, 2021

Summary of information about stock options under the Plan

				Weighted
		Weighted		Average
		Average		Remaining
	Number of	Exercise		Contractual	Intrinsic
	Shares	Price		Life (Years)	Value
	(in thousands, except per share and year data)
Balance at December 31, 2018	4,243	$	2.33	2.0	$	1,475
Granted	3,050		1.73	—		—
Exercised	(535)		1.01	—		419
Forfeited	(700)		2.56	—		—
Expired	(789)		2.90	—		—
Balance at December 31, 2019	5,269	$	2.00	3.0	$	364
Granted	5,097		1.22	—		—
Exercised	(135)		1.02	—		10
Forfeited	(1,968)		2.18	—		2
Expired	(1,251)		1.19	—		—
Balance at December 31, 2020	7,012	$	1.55	4.2	$	53
Granted	950		1.22	—		—
Exercised	—		—	—		10
Forfeited	(1,589)		1.46	—		2
Expired	(202)		7.10	—		—
Balance at December 31, 2021	6,171	$	1.34	4.2	$	53
Exercisable at December 31, 2021	2,265	$	1.47	2.6	$	—

Schedule of weighted-average assumptions used for estimation of the fair value of the options granted under the Plan at the date of grant, using the Black-Scholes Option Valuation Model

		2021		2020		2019
Risk-free interest rate		0.519% to 0.873%		0.157% to 0.322%		1.45% to 1.87%
Dividend yield		0.00%		0.00%		0.00%
Volatility factor of the expected market price of common stock		63%		59%		58%
Weighted-average expected life of option		3.5 years		3.5 years		3.5 years
Weighted-average grant date fair value	$	1.22	$	1.22	$	1.73

Summary of status and activity of non-vested stock options

		Weighted Average
		Grant Date
	Number of	Fair Value
	Shares	Per Share
	(in thousands, except per share amounts)
Non-vested, beginning of year	6,093	$	0.44
Granted	950	$	0.44
Cancelled/Forfeited	(1,339)	$	0.46
Vested	(1,799)	$	0.45
Non-vested, end of year	3,906	$	0.43

November 2019 Offering

Schedule of Black-Scholes pricing model to determine the fair value of warrants

	November 20, 2019
Risk-free interest rate		1.55	%
Dividend yield		0.00	%
Volatility factor of the expected market price of common stock		60	%
Weighted-average expected life		5 years
Weighted-average grant date fair value	$	0.52