Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance (in shares) at Dec. 31, 2015		11,084,318
Beginning Balance at Dec. 31, 2015	$ 185,734	$ 111	$ 0	$ 75,200	$ 116,026	$ (5,603)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	25,261				25,261
Other comprehensive income (loss), net of tax	(476)					(476)
Stock options exercised (in shares)		132,325
Stock options exercised	2,122	$ 1		2,121
Stock repurchased related to the exercise of stock options (in shares)		(151,916)
Stock repurchased related to the exercise of stock options	(3,465)	$ (1)		(3,464)
Stock awards vested (in shares)		129,086
Stock awards vested	0	$ 1		(1)
Stock-based compensation	3,007			3,007
Excess tax benefits or shortfall from share-based compensation	(80)			(80)
Ending Balance (in shares) at Dec. 31, 2016		11,193,813
Ending Balance at Dec. 31, 2016	212,103	$ 112	0	76,783	141,287	(6,079)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	20,077				20,077
Other comprehensive income (loss), net of tax	(38)					(38)
Stock options exercised (in shares)		212,775
Stock options exercised	4,336	$ 2		4,334
Stock repurchased related to the exercise of stock options (in shares)		(219,164)
Stock repurchased related to the exercise of stock options	(6,904)	$ (2)		(6,902)
Stock awards vested (in shares)		145,417
Stock awards vested	0	$ 1		(1)
Stock-based compensation	6,009			6,009
Ending Balance (in shares) at Dec. 31, 2017		11,332,841
Ending Balance at Dec. 31, 2017	235,583	$ 113	0	80,223	161,364	(6,117)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	9,035				9,035
Other comprehensive income (loss), net of tax	78					78
Adoption of ASU 2018-02 adjustment	$ (26)				1,292	(1,318)
Stock options exercised (in shares)	84,800	84,800
Stock options exercised	$ 1,822	$ 1		1,821
Stock repurchased related to the exercise of stock options (in shares)		(98,438)
Stock repurchased related to the exercise of stock options	(6,345)	$ (1)		(6,344)
Stock awards vested (in shares)		98,660
Stock awards vested	2,973	$ 1		2,972
Stock-based compensation	5,040			5,040
Ending Balance (in shares) at Dec. 31, 2018		11,417,863
Ending Balance at Dec. 31, 2018	$ 256,825	$ 114	$ 0	$ 83,712	$ 180,356	$ (7,357)