Condensed Consolidated Statement of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Capital Stock Preferred	Issued Common	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning Balance at Dec. 31, 2017	$ 168,730	$ 4	$ 6,715	$ 13,912	$ 167,129	$ (311)	$ (18,719)
Comprehensive income:
Net income	8,927				8,927
Other comprehensive income	(13)					(13)
Dividends and dividend equivalents of $.10 per common share and per restricted stock unit, net of estimated forfeitures	(1,374)				(1,374)
Share-based compensation	1,052			1,052
Stock shares awarded, forfeited, or vested	139			(981)			1,120
Purchase of treasury stock for tax withholding on share-based compensation	(2,073)						(2,073)
Ending Balance at Mar. 31, 2018	175,388	4	6,715	13,983	174,682	(324)	(19,672)
Comprehensive income:
Adjustment related to Accounting Standards Update 2018-02 adoption	0				(69)	69
Beginning Balance at Dec. 31, 2018	201,441	4	6,715	15,375	198,914	(164)	(19,403)
Comprehensive income:
Net income	9,720				9,720
Other comprehensive income	14					14
Dividends and dividend equivalents of $.10 per common share and per restricted stock unit, net of estimated forfeitures	(1,714)				(1,714)
Share-based compensation	1,031			1,031
Stock shares awarded, forfeited, or vested	94			(3,770)			3,864
Purchase of treasury stock for tax withholding on share-based compensation	(5,467)						(5,467)
Ending Balance at Mar. 31, 2019	$ 205,119	$ 4	$ 6,715	$ 12,636	$ 206,851	$ (81)	$ (21,006)