Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Treasury stock at cost	Accumulated other comprehensive loss
Balance at beginning of period at Dec. 31, 2019	$ 209,914	$ 172	$ 102,319	$ 131,228	$ (4,070)	$ (19,735)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,900)			(1,900)
Foreign currency translation adjustment	(5,681)					(5,681)
Repurchases of common stock	(1,826)				(1,826)
Stock-based compensation expense	1,213		1,213
Issuance of stock for employer contributions to retirement plan	1,579		(1,573)		3,152
Net issuances of stock pursuant to stock compensation plans and other	(558)		(1,936)		1,378
Balance at end of period at Jun. 30, 2020	202,741	172	100,023	129,328	(1,366)	(25,416)
Balance at beginning of period at Mar. 31, 2020	202,492	172	100,650	129,934	(1,374)	(26,890)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(606)			(606)
Foreign currency translation adjustment	1,474					1,474
Repurchases of common stock	(1,826)				(1,826)
Stock-based compensation expense	772		772
Issuance of stock for employer contributions to retirement plan	764		(511)		1,275
Net issuances of stock pursuant to stock compensation plans and other	(329)		(888)		559
Balance at end of period at Jun. 30, 2020	202,741	172	100,023	129,328	(1,366)	(25,416)
Balance at beginning of period at Dec. 31, 2020	223,346	173	103,225	138,296	(25)	(18,323)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,203			4,203
Foreign currency translation adjustment	783					783
Stock-based compensation expense	1,844		1,844
Issuance of stock for employer contributions to retirement plan	1,444	1	1,443
Net issuances of stock pursuant to stock compensation plans and other	(790)	1	(816)		25
Balance at end of period at Jun. 30, 2021	230,830	175	105,696	142,499	0	(17,540)
Balance at beginning of period at Mar. 31, 2021	226,596	174	104,664	140,020	0	(18,262)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,479			2,479
Foreign currency translation adjustment	722					722
Stock-based compensation expense	915		915
Issuance of stock for employer contributions to retirement plan	706		706
Net issuances of stock pursuant to stock compensation plans and other	(588)	1	(589)
Balance at end of period at Jun. 30, 2021	$ 230,830	$ 175	$ 105,696	$ 142,499	$ 0	$ (17,540)