Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tax Credit Carryforward [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 22,818	$ 15,826
Deferred tax assets	(168)	(137)
Deferred tax assets, valuation allowance	(62,379)	(39,365)
Unrecognized tax benefits	3,201	$ 1,954	$ 3,682
Unrecognized tax benefits that would impact effective tax rate	2,678
Unrecognized tax benefits, income tax penalties and interest expense	170
Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	137,833
Operating loss carryforwards, subject to expiration	22,907
Domestic Tax Authority | Accounting Standards Update 2018-02
Tax Credit Carryforward [Line Items]
Operating loss carryforwards			$ 22,907
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	105,082
Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 773
Israel Tax Authority | Foreign Tax Authority | VSL | Minimum
Tax Credit Carryforward [Line Items]
Tax rate for amount of dividends distributed, other than complete liquidation	10.00%
Israel Tax Authority | Foreign Tax Authority | VSL | Maximum
Tax Credit Carryforward [Line Items]
Tax rate for amount of dividends distributed, other than complete liquidation	25.00%
Research Tax Credit Carryforward | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	$ 1,412
Retention | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	24
Foreign Tax Credit | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	190
Ireland Employment | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	$ 43