CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Total
Balance at Dec. 31, 2013	$ 191	$ 30,926	$ 172,560	$ (39,797)	$ 163,880
Balance (in shares) at Dec. 31, 2013	16,482,768
Increase (Decrease) in Stockholders' Equity
Exercise of stock options		(9,553)		6,827	(2,726)
Exercise of stock options (in shares)	330,026
Excess tax benefit from stock-based compensation		386			386
Stock based compensation expense		1,226			1,226
Net income			14,185		14,185
Balance at Dec. 31, 2014	$ 191	22,985	186,745	(32,970)	176,951
Balance (in shares) at Dec. 31, 2014	16,812,794
Increase (Decrease) in Stockholders' Equity
Exercise of stock options		(2,666)		6,566	3,900
Exercise of stock options (in shares)	389,905
Excess tax benefit from stock-based compensation		865			865
Stock based compensation expense		1,544			1,544
Net income			20,659		20,659
Balance at Dec. 31, 2015	$ 191	22,728	207,404	(26,404)	$ 203,919
Balance (in shares) at Dec. 31, 2015	17,202,699				17,202,699
Increase (Decrease) in Stockholders' Equity
Exercise of stock options		(1,312)		4,246	$ 2,934
Exercise of stock options (in shares)	265,570
Excess tax benefit from stock-based compensation		737			737
Stock based compensation expense		1,681			1,681
Net income			24,574		24,574
Balance at Dec. 31, 2016	$ 191	$ 23,834	$ 231,978	$ (22,158)	$ 233,845
Balance (in shares) at Dec. 31, 2016	17,468,269				17,468,269