Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Deferred Compensation Trust [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 31, 2019	$ 815,226	$ 26	$ 260,871	$ 3,871	$ 558,200
Beginning Balance, Shares at Dec. 31, 2019		25,937,000
Stock compensation, including options and long-term incentives	6,306		6,306
Director deferred share activity	1,230		1,230
Director deferred share activity , Shares		132,000
Exercise of stock options less shares withheld for taxes	3,786		3,786
Exercise of stock options less shares withheld for taxes, Shares		108,000
Shares issued for long-term incentive awards, net of shares withheld for taxes, Shares		59,000
Shares issued for long-term incentive awards, net of shares withheld for taxes	(3,600)		(3,600)
Purchase of shares by Deferred Compensation Trust			1,275	(1,275)
Sale of shares by Deferred Compensation Trust			(2,202)	2,202
Net income	138,340				138,340
Ending Balance at Dec. 31, 2020	961,288	$ 26	267,666	(2,944)	696,540
Ending Balance, Shares at Dec. 31, 2020		26,236,000
Stock compensation, including options and long-term incentives	7,245		7,245
Director deferred share activity	1,458		1,458
Director deferred share activity , Shares		2,000
Exercise of stock options less shares withheld for taxes	3,678		3,678
Exercise of stock options less shares withheld for taxes, Shares		47,000
Shares issued for long-term incentive awards, net of shares withheld for taxes, Shares		52,000
Shares issued for long-term incentive awards, net of shares withheld for taxes	(6,571)		(6,571)
Purchase of shares by Deferred Compensation Trust			1,268	(1,268)
Sale of shares by Deferred Compensation Trust			(111)	111
Net income	253,235				253,235
Ending Balance at Dec. 31, 2021	1,220,333	$ 26	274,633	(4,101)	949,775
Ending Balance, Shares at Dec. 31, 2021		26,337,000
Stock compensation, including options and long-term incentives	7,657		7,657
Director deferred share activity	1,170		1,170
Director deferred share activity , Shares		2,000
Exercise of stock options less shares withheld for taxes	$ 4,511		4,511
Exercise of stock options less shares withheld for taxes, Shares	61,778	62,000
Shares issued for long-term incentive awards, net of shares withheld for taxes, Shares		63,000
Shares issued for long-term incentive awards, net of shares withheld for taxes	$ (11,752)		(11,752)
Purchase of shares by Deferred Compensation Trust			3,254	(3,254)
Sale of shares by Deferred Compensation Trust			(2,107)	2,107
Net income	357,422				357,422
Ending Balance at Dec. 31, 2022	$ 1,579,341	$ 26	$ 277,366	$ (5,248)	$ 1,307,197
Ending Balance, Shares at Dec. 31, 2022		26,464,000