Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	$ 34,052	$ 34,172
Balance at end of period	32,983	34,506
Foreign currency translation
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	(1,285)	(772)
Total other comprehensive (loss) income	104	416
Balance at end of period	(1,181)	(356)
Available-for-sale marketable securities
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	0	4
Other comprehensive (loss) income	0	(1)
Balance at end of period	0	3
Total accumulated other comprehensive loss
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	(1,285)	(768)
Balance at end of period	$ (1,181)	$ (353)