Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Changes in accumulated other comprehensive income, net of tax
Balance at December 31, 2018	$ 448
Other comprehensive loss and pension reclassification	(465)	$ 1,051
Balance at March 31, 2019	(17)
Foreign currency
Changes in accumulated other comprehensive income, net of tax
Balance at December 31, 2018	962
Other comprehensive loss and pension reclassification	(495)
Balance at March 31, 2019	467
Defined benefit pension plan
Changes in accumulated other comprehensive income, net of tax
Balance at December 31, 2018	(514)
Other comprehensive loss and pension reclassification	30
Balance at March 31, 2019	$ (484)