CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid- In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2018	$ 12	$ 8,802	$ (173)	$ 131,344	$ (30,879)	$ 109,106
Balance (in shares) at Dec. 31, 2018	12,117
Net income				20,750		20,750
Share-based compensation		990				990
Options exercised by executives and directors		269				269
Options exercised by executives and directors (in shares)	10
Net shares repurchased for employee taxes		(256)				(256)
Net shares repurchased for employee taxes, (in shares)	(1)
Other comprehensive income			127			127
Cash dividends declared to stockholders				(8,918)		(8,918)
Balance at Mar. 31, 2019	$ 12	9,805	(46)	143,176	(30,879)	122,068
Balance (in shares) at Mar. 31, 2019	12,126
Balance at Dec. 31, 2019	$ 12		25	168,788	(63,993)	104,832
Balance (in shares) at Dec. 31, 2019	12,272
Net income				18,477		18,477
Share-based compensation		981				981
Share-based compensation (in shares)	7
Net shares repurchased for employee taxes		(487)				(487)
Net shares repurchased for employee taxes, (in shares)	(5)
Treasury stock retired from stock repurchases				(63,993)	$ 63,993
Treasury stock retired from stock repurchases, (in shares)	(489)
Other comprehensive income			45			45
Cash dividends declared to stockholders				(13,099)		(13,099)
Balance at Mar. 31, 2020	$ 12	$ 494	$ 70	$ 110,173		$ 110,749
Balance (in shares) at Mar. 31, 2020	11,785