INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of United States and Foreign Income (Loss) Before Income Taxes and Minority Interest

	Years Ended December 31,
	2020			2019			2018
	(in thousands)
United States	$	(13,225	)	$	6,647		$	13,381
Foreign		(12,233	)		(10,591	)		(8,939	)
	$	(25,458	)	$	(3,944	)	$	4,442

Schedule of Components of the Benefit for Income Taxes

	Years Ended December 31,
	2020			2019			2018
	(in thousands)
Current
Federal	$	1		$	(984	)	$	—
State	—			—			—
Foreign		1,044			150		(890)
Total Current	$	1,045		$	(834	)	$	(890	)
Deferred
Federal	—			—			—
State	—			—			—
Foreign	(2,827)			803			512
Total Deferred	(2,827)			803			512
Total	$	(1,782	)	$	(31	)	$	(378	)

Summary of Unrecognized Tax Benefits

	Years Ended December 31,
	2020			2019				2018
	(in thousands)
Beginning balance-gross unrecognized tax benefits (UTB’s)	$	15,507		$	17,496			$	18,728
Lapse of statute of limitations		—			(291	)			(1,232	)
Tax credit expiration		(12,103	)		—				—
Rate change impact		—			(1,698	)			—
Ending balance—UTB		3,404			15,507		0		17,496
UTB’s as a credit in deferred taxes		(2,347	)		(12,905	)			(14,604	)
Federal benefit of state taxes		(516	)		(2,062	)			(2,063	)
UTB’s that would impact the effective tax rate	$	541		$	540			$	829

Summary of the Components of Net Deferred Tax Assets

	December 31,			December 31,
	2020			2019
	(in thousands)
Deferred Tax Assets
Allowance and reserves	$	5,681		$	2,935
Prepaid expense		93			95
Net operating loss carryforward		166,297			162,712
Tax credit carryforwards		6,881			5,660
Writedown/amortization of intangible assets and goodwill		1			15
Property, plant and equipment		815			4,147
Demo equipment income		74			4,588
Accrued warranties		12			25
Other		13,874			15,193
Total deferred tax assets		193,728			195,370
Deferred Tax Liabilities
Deferred revenue and customer advances, net		(204	)		(157	)
Total deferred tax liabilities		(204	)		(157	)
Total net deferred tax assets		193,524			195,213
Less: Valuation allowance		(189,253	)		(193,788	)
Total net deferred tax assets	$	4,271		$	1,425

Schedule of Reconciliation of Effective Income Tax Amount and the Federal Statutory Amount

	Years Ended December 31,
	2020			2019			2018
	(in thousands)
Federal tax (benefit) at statutory rate	$	(5,388	)	$	(858	)	$	1,120
Stock compensation expense		148			132			184
Effect of differences in foreign tax rates		(1,408	)		547			2,113
ASC 460 reserve		22			(349	)		(1,230	)
Change in deferred tax valuation allowance		4,334			1,107			(1,679	)
Other		510			(610	)		(886	)
Total Tax Benefit	$	(1,782	)	$	(31	)	$	(378	)