Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income	$ 27,292	$ 19,913	$ 39,351	$ 26,258
Other comprehensive income (loss):
Foreign currency translation adjustment	2,815	998	(3,083)	1,840
Minimum pension and post retirement benefit plan adjustments	18	12	36	24
Other comprehensive income (loss)	2,833	1,010	(3,047)	1,864
Total comprehensive income	$ 30,125	$ 20,923	$ 36,304	$ 28,122