Income Taxes - components of the Company's deferred tax (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
U.S. NOL	$ 23,585	$ 17,471
Foreign NOL	5,967	6,846
U.S. capital loss carryover	4,371	4,377
Accrued payroll and expense		172
Nonqualified options	1,927	772
Convertible notes	827	752
Impaired assets	7,996	1,436
Equity investment loss and others	3,596	115
Total deferred tax assets	48,269	31,941
Less: valuation allowance	(46,670)	(30,276)
Property and equipment	(76)	(36)
Intangible assets	(1,523)	(1,629)
Deferred Tax liabilities	$ (1,599)	$ (1,665)

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible convertible notes

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as nonqualified options.

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Amount of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible capital loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic operating loss carryforwards. Excludes state and local operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign operating loss carryforwards.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from estimated impairment losses.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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