CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Treasury Stock	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)
Balance, shares at Dec. 31, 2018		1,567	1,853
Balance, amount at Dec. 31, 2018	$ 210,767	$ (131,727)	$ 342	$ 50,391	$ 291,761
Net income	19,102				19,102
Stock-based compensation transactions, shares		(3)	3
Stock-based compensation transactions, amount	987	$ 46		941
Shares surrendered in stock transactions, shares		1	(1)
Shares surrendered in stock transactions, amount	(579)	$ (579)
Dividends	(5,017)				(5,017)
Balance, shares at Jun. 30, 2019		1,565	1,855
Balance, amount at Jun. 30, 2019	225,260	$ (132,260)	$ 342	51,332	305,846
Balance, shares at Mar. 31, 2019		1,567	1,853
Balance, amount at Mar. 31, 2019	218,083	$ (131,721)	$ 342	50,772	298,690
Net income	9,664				9,664
Stock-based compensation transactions, shares		(3)	3
Stock-based compensation transactions, amount	600	$ 40		560
Shares surrendered in stock transactions, shares		1	(1)
Shares surrendered in stock transactions, amount	(579)	$ (579)
Dividends	(2,508)				(2,508)
Balance, shares at Jun. 30, 2019		1,565	1,855
Balance, amount at Jun. 30, 2019	225,260	$ (132,260)	$ 342	51,332	305,846
Balance, shares at Dec. 31, 2019		1,565	1,855
Balance, amount at Dec. 31, 2019	237,870	$ (132,260)	$ 342	52,043	317,745
Net income	17,502				17,502
Stock-based compensation transactions, amount	1,000	23		977
Shares surrendered in stock transactions, amount	(55)	$ (55)
Dividends	(5,717)				(5,717)
Cumulative change in accounting principal	(36)				(36)
Purchase of treasury stock, shares		26	(26)
Purchase of treasury stock, amount	(17,037)	$ (17,037)
Balance, shares at Jun. 30, 2020		1,591	1,829
Balance, amount at Jun. 30, 2020	233,527	$ (149,329)	$ 342	53,020	329,494
Balance, shares at Mar. 31, 2020		1,580	1,840
Balance, amount at Mar. 31, 2020	234,997	$ (141,500)	$ 342	52,422	323,733
Net income	8,605				8,605
Stock-based compensation transactions, amount	616	18		598
Shares surrendered in stock transactions, amount	(55)	$ (55)
Dividends	(2,844)				(2,844)
Purchase of treasury stock, shares		11	(11)
Purchase of treasury stock, amount	(7,792)	$ (7,792)
Balance, shares at Jun. 30, 2020		1,591	1,829
Balance, amount at Jun. 30, 2020	$ 233,527	$ (149,329)	$ 342	$ 53,020	$ 329,494