Income Taxes (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Deferred tax asset:
Net operating loss carryforward	$ 18,077	$ 17,801
Expenses capitalized under IRC 263(a)	37	37
Tax credits (AMT)	57	57
Valuation allowance	(18,171)	(17,895)
Total deferred tax asset	$ 0	$ 0