Condensed Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Shares [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock, Common
Shares Outstanding, Beginning Balance at Dec. 31, 2022		27,440,083
Stockholders' Equity, Beginning Balance at Dec. 31, 2022	$ 2,070,725	$ 301	$ 352,639	$ 1,835,983	$ (118,198)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	103,066			103,066
Stock options exercised, shares		218,066
Stock options exercised	6,439		(3,118)		9,557
Stock-based compensation expense	2,023		2,023
Deferral of executive and director compensation	962		962
Deferred Compensation Arrangement with Individual, Shares Issued		57,467
Deferred Compensation Arrangement with Individual, Distribution Paid	0		(2,518)		2,518
Shares Outstanding, Ending Balance at Mar. 31, 2023		27,715,616
Stockholders' Equity, Ending Balance at Mar. 31, 2023	2,183,215	$ 301	349,988	1,939,049	(106,123)
Shares Outstanding, Beginning Balance at Dec. 31, 2023		27,761,299
Stockholders' Equity, Beginning Balance at Dec. 31, 2023	2,516,939	$ 301	349,907	2,301,348	(134,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	138,061			138,061
Stock options exercised, shares		135,300
Stock options exercised	5,495		(2,299)		7,794
Stock-based compensation expense	$ 3,539		3,539
Repurchase of common shares, shares	200,000	(200,000)
Repurchase of common shares	$ (25,278)				(25,278)
Deferral of executive and director compensation	29		29
Deferred Compensation Arrangement with Individual, Shares Issued		55,059
Deferred Compensation Arrangement with Individual, Distribution Paid	0		(3,137)		3,137
Shares Outstanding, Ending Balance at Mar. 31, 2024		27,751,658
Stockholders' Equity, Ending Balance at Mar. 31, 2024	$ 2,638,785	$ 301	$ 348,039	$ 2,439,409	$ (148,964)