Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Tax benefit from TCJA	$ 3,800
Deferred tax liability from outside basis difference	400
Undistributed earnings of foreign subsidiaries		$ 13,600
GILTI	200
Operating loss carryforwards, subject to expiration	20,400
Operating loss carryforwards, not subject to expiration	20,800
Valuation allowance	19,627	15,910
Reasonably possible decrease in unrecognized tax benefits in the next twelve months	400
U.S.
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	41,200
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	18,600
Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	700
TSR
Operating Loss Carryforwards [Line Items]
Valuation allowance	19,600	15,900
Tax Year Prior to 2017
Operating Loss Carryforwards [Line Items]
Payments of tax settlements		$ 4,300
Tax Year 2017
Operating Loss Carryforwards [Line Items]
Payments of tax settlements	$ 600