Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Capital Stock, Common	Additional Paid-in Capital	Retained Earnings	Treasury Stock
Balance at Dec. 31, 2018	$ 615,972	$ 907	$ 3,454	$ 760,262	$ (148,651)
Net income	72,967	0	0	72,967	0
Dividends on common stock	(6,563)	0	0	(6,563)	0
Stock Issued During Period, Value	750	0	113	0	637
Stock-based compensation, net of tax	1,533	0	574	0	959
Balance at Dec. 31, 2019	684,659	907	4,141	826,666	(147,055)
Net income	70,806	0	0	70,806	0
Dividends on common stock	(6,502)	0	0	(6,502)	0
Stock Repurchased During Period, Value	(26,139)	0	0	0	(26,139)
Stock-based compensation, net of tax	1,510	0	189	0	1,321
Balance at Dec. 31, 2020	724,334	907	4,330	890,970	(171,873)
Net income	79,277	0	0	79,277	0
Dividends on common stock	(45,872)	0	0	(45,872)	0
Stock Repurchased During Period, Value	(31,540)	0	0	0	(31,540)
Stock-based compensation, net of tax	903	0	(189)	0	1,092
Balance at Dec. 31, 2021	$ 727,102	$ 907	$ 4,141	$ 924,375	$ (202,321)