Income Taxes - Change In Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in valuation allowance
Increase in valuation allowance for current year increase in net operating losses	$ 7,622
Increase (decrease) in valuation allowance for current year net increase (decrease) in deferred tax assets other than net operating losses	11,786
Decrease in valuation allowance as a result of foreign currency fluctuation	(2,935)
Increase in valuation allowance due to change in tax rates	387
Net increase in Valuation allowance	16,860
Net decrease (increase) in valuation allowance	16,860	$ 10,735	$ (11,619)
U.S.
Change in valuation allowance
Increase in valuation allowance for current year increase in net operating losses	7,254
Increase (decrease) in valuation allowance for current year net increase (decrease) in deferred tax assets other than net operating losses	11,845
Decrease in valuation allowance as a result of foreign currency fluctuation	(2,935)
Net increase in Valuation allowance	16,164
Net decrease (increase) in valuation allowance	16,164	11,003	(12,167)
Foreign
Change in valuation allowance
Increase in valuation allowance for current year increase in net operating losses	368
Increase (decrease) in valuation allowance for current year net increase (decrease) in deferred tax assets other than net operating losses	(59)
Increase in valuation allowance due to change in tax rates	387
Net increase in Valuation allowance	696
Net decrease (increase) in valuation allowance	$ 696	$ (268)	$ 548