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, 2016		11,193,813
Beginning 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)
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)
Exercised (in shares)		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	(3,372)	$ (1)		(3,371)
Stock awards vested (in shares)		98,660
Stock awards vested	0	$ 1		(1)
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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	32,461
Other comprehensive income (loss), net of tax	(911)					(911)
Employee stock purchase plan (in shares)		26,521
Employee stock purchase plan	$ 1,118			1,118
Exercised (in shares)	80,693	80,693
Stock options exercised	$ 2,015	$ 1		2,014
Stock repurchased related to the exercise of stock options (in shares)		(123,192)
Stock repurchased related to the exercise of stock options	(5,605)	$ (1)		(5,604)
Stock awards vested (in shares)		170,783
Stock awards vested	0	$ 2		(2)
Stock-based compensation	7,161			7,161
Ending Balance (in shares) at Dec. 31, 2019		11,572,668
Ending Balance at Dec. 31, 2019	$ 292,800	$ 116	$ 0	$ 88,399	$ 212,553	$ (8,268)