SHAREHOLDERS' EQUITY (Tables)

12 Months Ended

Dec. 31, 2019

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, 2016	4,720	$	2.41	3.4	$	4,388
Granted	338		2.99	—		—
Exercised	(94)		1.30	—		87
Forfeited	(37)		4.28	—		—
Expired	(21)		5.00	—		—
Balance at December 31, 2017	4,906	$	2.45	2.6	$	2,564
Granted	375		1.90	—		—
Exercised	(171)		1.02	—		195
Forfeited	(405)		3.99	—		—
Expired	(462)		2.27	—		—
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
Exercisable at December 31, 2019	2,234	$	2.27	1.2	$	364

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

		2019		2018		2017
Risk-free interest rate		1.45% to 1.87%		2.67% to 2.89%		1.46% to 1.60%
Dividend yield		0.00%		0.36% to 0.53%		0.31% to 0.36%
Volatility factor of the expected market price of common stock		58%		63% to 64%		72% to 74%
Weighted-average expected life of option		3.5 years		3.5 years		3.5 years
Weighted-average grant date fair value	$	1.73	$	1.90	$	2.99

Summary of status and activity of non-vested stock options

		Weighted
		Average
	Number of	Grant Date
	Shares	Fair Value
	(in thousands, except per share amounts)
Non-vested, beginning of year	691	$	1.28
Granted	3,050	$	0.58
Cancelled/Forfeited	(402)	$	0.74
Vested	(304)	$	1.44
Non-vested, end of year	3,035	$	0.64

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

March 2019 Offering

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

Issued on:	March 29, 2019			May 23, 2019
Risk-free interest rate		2.30	%		2.14	%
Dividend yield		0.00	%		0.00	%
Volatility factor of the expected market price of common stock		50	%		45	%
Weighted-average expected life		3 years			3 years
Weighted-average grant date fair value	$	0.43		$	0.22

September 2017 Offering

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

Risk-free interest rate		1.56	%
Dividend yield		0.36	%
Volatility factor of the expected market price of common stock		71	%
Weighted-average expected life		53 weeks
Weighted-average grant date fair value	$	0.40