Summary of Significant Accounting Policies - Components of Other Non-Operating (Income) Expense Recognized in Condensed Consolidated Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Nonoperating Income Expense [Abstract]
Interest Income	$ (72)	$ (776)	$ (479)	$ (1,714)
Foreign currency (gains) losses, net	166	305	344	323
Gain on sale of a private company investment	0	0	(1,001)	(1,001)
Other (income) expense, net	8	(104)	2	(162)
Other non-operating (income) expense, net	$ 102	$ (575)	$ (1,134)	$ (2,554)