Income Taxes (Details 3) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income taxes
Deferred tax benefit		$ 3,400,000
Adjustments to provisional amount	$ 0
Valuation allowance	31,170,000	28,350,000	$ 40,148,000
Unrecognized tax benefits	0	206,000	$ 967,000
Interest and penalties	0	0
Interest and penalties accrued	$ 0	$ 0
State \| Minimum
Income taxes
Open Tax Year	2013
Federal \| Minimum
Income taxes
Open Tax Year	2015
Foreign \| Minimum
Income taxes
Open Tax Year	2015

Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit)

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Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of valuation and qualifying accounts and reserves.

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