Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Employee Stock Loans [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2017	$ 374,144	$ 161	$ 331,339	$ 65,512	$ (3,092)	$ (121)	$ (19,655)
Beginning balance, shares at Dec. 31, 2017		14,605,607
Net income (loss)	8,711			8,711
Other comprehensive (loss) income, net of tax effects	(2,104)				(2,104)
Stock based compensation	718		718
Common stock issued upon exercise of stock options	18		18
Common stock issued upon exercise of stock options, shares		1,250
Common stock issued under stock-based incentive plan, shares		2,557
Adoption of ASU | ASU 2016-01 [Member]				(11)	11
Ending balance at Mar. 31, 2018	381,487	$ 161	332,075	74,212	(5,185)	(121)	(19,655)
Ending balance, shares at Mar. 31, 2018		14,609,414
Beginning balance at Dec. 31, 2018	455,941	$ 173	379,085	101,326	(4,867)	(121)	(19,655)
Beginning balance, shares at Dec. 31, 2018		15,793,095
Net income (loss)	(4,073)			(4,073)
Other comprehensive (loss) income, net of tax effects	2,100				2,100
Stock based compensation	734		734
Common stock issued upon exercise of stock options	112		112
Common stock issued upon exercise of stock options, shares		6,100
Common stock issued under stock-based incentive plan, shares		21,108
Repayment on employee stock loans	34					34
Adoption of ASU | ASU 2017-08 [Member]	(1,385)			(1,385)
Ending balance at Mar. 31, 2019	$ 453,463	$ 173	$ 379,931	$ 95,868	$ (2,767)	$ (87)	$ (19,655)
Ending balance, shares at Mar. 31, 2019		15,820,303