Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 6,606	$ 8,608	$ 13,376	$ 15,452
Other comprehensive income (loss)
Adoption of ASU 2018-02				(315)
Foreign currency translation adjustment	758	(123)	1,535	(1,843)
Pension liability, net of tax expense of $67 in 2018				201
Total other comprehensive income (loss)	758	(123)	1,535	(1,957)
Comprehensive income	$ 7,364	$ 8,485	$ 14,911	$ 13,495