CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Capital in excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance (in shares) at Dec. 31, 2016		17,479,000				(1,708,000)
Balance at Dec. 31, 2016	$ 69,580	$ 350	$ 46,203	$ 32,357	$ (3,494)	$ (5,836)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,386)			(3,386)
Issuance of common stock upon the exercise of stock options (in shares)		271,000
Issuance of common stock upon the exercise of stock options	1,500	$ 5	1,495
Repurchase of common stock (in shares)		(54,000)
Repurchase of common stock	(1)	$ (1)
Equity based compensation	651		651
Net issuance of restricted stock awards (in shares)		(19,000)
Net issuance of restricted stock awards	0
Foreign currency translation adjustments	$ 64				64
Balance (in shares) at Dec. 31, 2017	15,969,052	17,677,000				(1,708,000)
Balance at Dec. 31, 2017	$ 68,986	$ 354	48,349	29,549	(3,430)	$ (5,836)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of accounting standard	578
Net loss	$ (24,122)			(24,122)
Issuance of common stock upon the exercise of stock options (in shares)	168,000	168,000
Issuance of common stock upon the exercise of stock options	$ 866	$ 3	863
Equity based compensation	1,039		1,039
Net issuance of restricted stock awards (in shares)		16,000
Net issuance of restricted stock awards	0	$ 0
Foreign currency translation adjustments	$ (823)				(823)
Balance (in shares) at Dec. 31, 2018	16,171,652	17,861,000				(1,708,000)
Balance at Dec. 31, 2018	$ 45,946	$ 357	$ 50,251	$ 5,427	$ (4,253)	$ (5,836)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of accounting standard	$ 0