Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes (Details) [Line Items]
Income Tax Expense (Benefit)	$ 735	$ 1,912	$ 2,951
Effective Income Tax Rate Reconciliation, Percent	5.50%	3.60%	7.50%
Discrete Net Tax Expense Benefit	$ (300)
Effective Income Tax Rate, Continuing Operations, Excluding Discrete Items	7.70%	3.10%	9.60%
Deferred Tax Liabilities, Net	$ 100	$ 14
Unrecognized Tax Benefits, Period Increase (Decrease)	(600)
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions		100	$ 600
Unrecognized Tax Benefits, Interest on Income Taxes Expense		40	$ 100
Deferred Tax Assets, Valuation Allowance	92,764	$ 92,778
U.S. Federal net operating loss carryforwards	190,200
Foreign Tax Authority [Member]
Income Taxes (Details) [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	100
Research Tax Credit Carryforward [Member] | Domestic Tax Authority [Member]
Income Taxes (Details) [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Research	500
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member]
Income Taxes (Details) [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Research	$ 100