Accumulated Other Comprehensive Income (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Accumulated Other Comprehensive Income
Period Start Balance	$ 124,060
Period End Balance	101,380
Amounts reclassified from AOCI	0
Unrealized Gain/(Loss) on Marketable Securities
Accumulated Other Comprehensive Income
Period Start Balance	(13)
Other comprehensive gain	52
Period End Balance	39
Foreign Currency Items
Accumulated Other Comprehensive Income
Period Start Balance	2,596
Period End Balance	2,596
Accumulated Other Comprehensive Income.
Accumulated Other Comprehensive Income
Period Start Balance	2,583
Other comprehensive gain	52
Period End Balance	$ 2,635