Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

The provision for income taxes consisted of the following components for the years ended December 31:

	2020		2019
Current:
Federal	$	(326)	$	—
State	578		5
Total current	252		5
Deferred:
Federal	—		—
State	—		—
Total deferred	—		—
Total provision for income taxes	$	252	$	5

Reconciliation of Federal Statutory Income Tax Rate

Reconciliation of the Federal statutory income tax rate of 21% to the effective rate is as follows:

	2020		2019		2018
Federal statutory income (benefit) tax rate	21.00	%	21.00	%	21.00	%
State taxes, net of federal benefit	1.75		(0.18)		(0.11)
Stock compensation	4.47		(5.39)		(4.74)
Permanent differences-other	3.77		(7.67)		(1.33)
CARES Act 163(j) Modifications	2.95		—		—
Other	3.94		1.71		(2.07)
Decrease (increase) in valuation allowance	(36.91)		(9.44)		(12.65)
	0.97	%	0.03	%	0.10	%

Significant Components of Deferred Tax Assets and Liabilities

The tax effects of temporary differences and net operating losses that give rise to significant components of deferred tax assets and liabilities consist of the following:

	December 31,
Deferred tax assets	2020		2019
Net operating loss carry-forward	$58,520		$62,535
R&D credit	10,930		10,980
Accrued liabilities and other	1,004		3,942
Stock options	850		4,416
Less: valuation allowance	(66,495)		(76,079)
Net deferred tax assets	4,809		5,794
Deferred tax liabilities
Basis difference in intangibles	(4,696)		(5,356)
Basis difference in equipment	(113)		(438)
Total net deferred tax asset	$	—	$	—