Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]
BALANCE at Dec. 31, 2022	$ 725,845	$ 894	$ (301,624)	$ 684,183	$ (5,447)	$ 347,839
BALANCE, shares at Dec. 31, 2022		89,396,000
BALANCE, shares at Dec. 31, 2022			(22,221,000)
Net income	130,464					130,464
Foreign currency translation	(8)				(8)
Unrealized gain on investments, net of tax	456				456
Dividends to shareholders	(7,474)					(7,474)
Treasury stock purchased	(2,729)		$ (2,729)
Treasury stock purchased, shares			(221,000)
Treasury stock acquired upon sale of asset	(22,086)		$ (22,086)
Treasury stock acquired upon sale of asset, shares			(1,800,000)
Share-based compensation expense	6,651			6,651
Common stock issued	(1,460)	$ 7	$ (2,209)	742
Common stock issued, shares		680,000	(165,000)
BALANCE at Sep. 30, 2023	829,659	$ 901	$ (328,648)	691,576	(4,999)	470,829
BALANCE, shares at Sep. 30, 2023		90,076,000
BALANCE, shares at Sep. 30, 2023			(24,407,000)
BALANCE at Jun. 30, 2023	792,432	$ 900	$ (328,648)	688,805	(5,621)	436,996
BALANCE, shares at Jun. 30, 2023		90,016,000
BALANCE, shares at Jun. 30, 2023			(24,407,000)
Net income	41,307					41,307
Foreign currency translation	(31)				(31)
Unrealized gain on investments, net of tax	653				653
Dividends to shareholders	(7,474)					(7,474)
Share-based compensation expense	2,336			2,336
Common stock issued	436	$ 1		435
Common stock issued, shares		60,000
BALANCE at Sep. 30, 2023	829,659	$ 901	$ (328,648)	691,576	(4,999)	470,829
BALANCE, shares at Sep. 30, 2023		90,076,000
BALANCE, shares at Sep. 30, 2023			(24,407,000)
BALANCE at Dec. 31, 2023	$ 841,421	$ 903	$ (334,220)	694,798	(666)	480,606
BALANCE, shares at Dec. 31, 2023	90,270,306	90,270,000
BALANCE, shares at Dec. 31, 2023	(24,725,767)		(24,726,000)
Net income	$ 116,126					116,126
Foreign currency translation	7				7
Unrealized gain on investments, net of tax	2,227				2,227
Dividends to shareholders	(23,701)					(23,701)
Treasury stock purchased	(6,769)		$ (6,769)
Treasury stock purchased, shares			(385,000)
Share-based compensation expense	7,385			7,385
Common stock issued	(1,265)	$ 7	$ (3,435)	2,163
Common stock issued, shares		751,000	(193,000)
BALANCE at Sep. 30, 2024	$ 935,431	$ 910	$ (344,424)	704,346	1,568	573,031
BALANCE, shares at Sep. 30, 2024	91,020,793	91,021,000
BALANCE, shares at Sep. 30, 2024	(25,304,436)		(25,304,000)
BALANCE at Jun. 30, 2024	$ 899,524	$ 910	$ (344,424)	701,153	(1,721)	543,606
BALANCE, shares at Jun. 30, 2024		90,978,000
BALANCE, shares at Jun. 30, 2024			(25,304,000)
Net income	38,255					38,255
Foreign currency translation	46				46
Unrealized gain on investments, net of tax	3,243				3,243
Dividends to shareholders	(8,830)					(8,830)
Share-based compensation expense	2,828			2,828
Common stock issued	365			365
Common stock issued, shares		43,000
BALANCE at Sep. 30, 2024	$ 935,431	$ 910	$ (344,424)	$ 704,346	$ 1,568	$ 573,031
BALANCE, shares at Sep. 30, 2024	91,020,793	91,021,000
BALANCE, shares at Sep. 30, 2024	(25,304,436)		(25,304,000)