Income Taxes (Details 2)	9 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
U. S. statutory income tax rate		21.00%	34.00%
Non-deductible expenses:
Non-deductible stock awards		(1.20%)	0.00%
Waiver of intercompany loan related to ZHV disposal		0.00%	14.70%
Others		(0.90%)	(2.90%)
Non-deductible interest expenses		(0.60%)	(0.40%)
Non-taxable change in fair value warrant liabilities		0.00%	(0.40%)
Increase in valuation allowance		(18.40%)	(21.60%)
Tax rate differential		0.10%	(23.40%)
Effective income tax rate	4.43%	0.00%	0.00%

Effective Income Tax Rate Reconciliation Nondeductible Expense Earn Out Shares Expense.

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Effective Income Tax Rate Reconciliation Nondeductible Expense Tax Rate Differential Percent.

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Represents percentage 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 nondeductible interest expenses.

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Waiver of intercompany loan related to ZHV disposal.

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

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage 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 changes in the valuation allowance for deferred tax assets.

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