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		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Nonoperating Income Expense [Abstract]
Interest Income	$ (142)	$ (141)	$ (405)	$ (620)
Foreign currency (gains) losses, net	289	(151)	738	193
Gain on sale of a private company investment	0	0	0	(1,001)
Other expense, net	396	149	406	151
Other non-operating (income) expense, net	$ 543	$ (143)	$ 739	$ (1,277)