Income Taxes Operating losses and credit carryforwards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Foreign income tax holiday, term	15 years
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 43,116	$ 42,981
Tax Credit Carryforward, Amount	901	4,679
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	38,307	25,186
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	40,349	29,852
Tax Credit Carryforward, Amount	$ 42,755	$ 38,364