Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Provision for income taxes [Abstract]
Income taxes using U.S federal statutory rate	$ (5,073)	$ (1,865)
Nondeductible interest	315	994
Loss on extinguishment of debt		361
Loss of tax benefit of state net operating loss carryforwards	(11)	1,477
Loss of tax benefit of federal tax credit carryforwards		324
Branch income	(238)
State income taxes, net of federal benefit	(1,788)	(1,461)
Foreign rate differential	(238)	664
Valuation allowance	6,281	3,512
Derivative charge	595	(3,674)
Stock option exercises and cancellations	308
Research and development costs	(166)	(316)
Other	15	(16)
Total	$ 0	$ 0

Income tax rate reconciliation state operating loss carryforwards.

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Income tax reconciliation branch income

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to derivative costs.

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Income tax reconciliation, federal tax credits.

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Income tax reconciliation loss on extinguishment of debt.

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Income tax reconciliation, nondeductible expense, interest.

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Valuation allowance deferred tax asset change in amount charged to costs and expenses.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority noncontrolling interest income (loss), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, increase (decrease) in enacted tax rate, prior year income taxes, increase (decrease) in deferred tax asset valuation allowance, and other adjustments.

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