Unaudited Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]
Beginning balance, value at Dec. 31, 2021	$ 893,714	$ 623	$ 465,594	$ 915,579		$ (488,082)
Beginning balance, shares at Dec. 31, 2021		62,298				4,286
Vesting of restricted stock, shares		4
Stock-based compensation	24,713		24,713
Repurchases of common stock	(218)					$ (218)
Repurchases of common stock, shares						1
Net income	91,930			91,930
Other comprehensive earnings (loss), net of tax	(1,119)				$ (1,119)
Ending balance, value at Mar. 31, 2022	1,009,020	$ 623	490,307	1,007,509	(1,119)	$ (488,300)
Ending balance, shares at Mar. 31, 2022		62,302				4,287
Beginning balance, value at Dec. 31, 2021	893,714	$ 623	465,594	915,579		$ (488,082)
Beginning balance, shares at Dec. 31, 2021		62,298				4,286
Net income	201,438
Ending balance, value at Sep. 30, 2022	1,076,380	$ 625	550,302	1,117,017	(3,813)	$ (587,751)
Ending balance, shares at Sep. 30, 2022		62,517				4,650
Beginning balance, value at Mar. 31, 2022	1,009,020	$ 623	490,307	1,007,509	(1,119)	$ (488,300)
Beginning balance, shares at Mar. 31, 2022		62,302				4,287
Vesting of restricted stock		$ 2	(2)
Vesting of restricted stock, shares		212
Stock-based compensation	27,472		27,472
Repurchases of common stock	(99,227)					$ (99,227)
Repurchases of common stock, shares						363
Net income	57,355			57,355
Other comprehensive earnings (loss), net of tax	(481)				(481)
Ending balance, value at Jun. 30, 2022	994,139	$ 625	517,777	1,064,864	(1,600)	$ (587,527)
Ending balance, shares at Jun. 30, 2022		62,514				4,650
Vesting of restricted stock, shares		3
Stock-based compensation	32,525		32,525
Repurchases of common stock	(224)					$ (224)
Net income	52,153			52,153
Other comprehensive earnings (loss), net of tax	(2,213)				(2,213)
Ending balance, value at Sep. 30, 2022	1,076,380	$ 625	550,302	1,117,017	(3,813)	$ (587,751)
Ending balance, shares at Sep. 30, 2022		62,517				4,650
Beginning balance, value at Dec. 31, 2022	1,182,607	$ 625	576,622	1,196,968	(3,703)	$ (587,905)
Beginning balance, shares at Dec. 31, 2022		62,518				4,651
Vesting of restricted stock, shares		7
Stock-based compensation	32,344		32,344
Repurchases of common stock	(626)					$ (626)
Repurchases of common stock, shares						2
Net income	119,296			119,296
Other comprehensive earnings (loss), net of tax	850				850
Ending balance, value at Mar. 31, 2023	1,334,471	$ 625	608,966	1,316,264	(2,853)	$ (588,531)
Ending balance, shares at Mar. 31, 2023		62,525				4,653
Beginning balance, value at Dec. 31, 2022	1,182,607	$ 625	576,622	1,196,968	(3,703)	$ (587,905)
Beginning balance, shares at Dec. 31, 2022		62,518				4,651
Net income	259,031
Ending balance, value at Sep. 30, 2023	1,421,309	$ 627	687,723	1,410,659	(2,181)	$ (675,519)
Ending balance, shares at Sep. 30, 2023		62,655				4,955
Beginning balance, value at Mar. 31, 2023	1,334,471	$ 625	608,966	1,316,264	(2,853)	$ (588,531)
Beginning balance, shares at Mar. 31, 2023		62,525				4,653
Vesting of restricted stock		$ 1	(1)
Vesting of restricted stock, shares		115
Stock-based compensation	41,000		41,000
Repurchases of common stock	(10,441)					$ (10,441)
Repurchases of common stock, shares						38
Dividends declared	(22,721)			(22,721)
Net income	64,516			64,516
Other comprehensive earnings (loss), net of tax	(140)				(140)
Ending balance, value at Jun. 30, 2023	1,406,685	$ 626	649,965	1,358,059	(2,993)	$ (598,972)
Ending balance, shares at Jun. 30, 2023		62,640				4,691
Vesting of restricted stock	1	$ 1
Vesting of restricted stock, shares		150
Stock-based compensation	37,758		37,758
Repurchases of common stock	(76,547)					$ (76,547)
Repurchases of common stock, shares						264
Dividends declared	(22,619)			(22,619)
Net income	75,219			75,219
Other comprehensive earnings (loss), net of tax	812				812
Ending balance, value at Sep. 30, 2023	$ 1,421,309	$ 627	$ 687,723	$ 1,410,659	$ (2,181)	$ (675,519)
Ending balance, shares at Sep. 30, 2023		62,655				4,955