Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 9,990	$ (9,570)	$ 15,380
Other comprehensive income (loss), net of tax:
Foreign currency translation	4,884	401	(3,257)
Net change in market value of interest rate swap	(717)	(104)
Net change in market value of investments			141
Other comprehensive income (loss)	4,167	297	(3,116)
Comprehensive income (loss)	$ 14,157	$ (9,273)	$ 12,264