Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Capital Surplus	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss), Net of Tax	Treasury Stock
Balance at beginning of period (in shares) at Dec. 31, 2021			72,017,126
Balance at beginning of period at Dec. 31, 2021	$ 2,966,451		$ 72,017	$ 1,924,813	$ 1,006,436		$ 15,590	$ (52,405)
Balance at beginning of period (in shares) at Dec. 31, 2021								2,407,898
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted shares (in shares)			165,687
Issuance of restricted shares	1,341		$ 166	1,175
Forfeitures of restricted shares (in shares)			(14,889)
Forfeitures of restricted shares	(143)		$ (15)	(128)
Proceeds from exercise of stock options (in shares)			95,803
Proceeds from the exercise of stock options	2,799		$ 96	2,703
Share-based compensation	6,648			6,648
Purchase of treasury shares (in shares)								486,779
Purchase of treasury shares	(22,421)							$ (22,421)
Net income	346,540				346,540
Dividends on common shares	(41,718)				(41,718)
Other comprehensive income (loss) during the period	$ (62,097)						(62,097)
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-13 [Member]
Balance at end of period (in shares) at Dec. 31, 2022			72,263,727
Balance at end of period at Dec. 31, 2022	$ 3,197,400		$ 72,264	1,935,211	1,311,258		(46,507)	$ (74,826)
Balance at end of period (in shares) at Dec. 31, 2022								2,894,677
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle for ASU 2022-02		$ 1,277				$ 1,277
Issuance of restricted shares (in shares)			133,430
Issuance of restricted shares	0		$ 133	(133)
Issuance of common shares pursuant to PSU agreements (in shares)			105,005
Issuance of common shares pursuant to PSU agreements	0		$ 105	(105)
Forfeitures of restricted shares (in shares)			(2,083)
Forfeitures of restricted shares	(32)		$ (2)	(30)
Proceeds from exercise of stock options (in shares)			16,000
Proceeds from the exercise of stock options	476		$ 16	460
Share-based compensation	9,982			9,982
Purchase of treasury shares (in shares)								568,061
Purchase of treasury shares	(20,346)							$ (20,346)
Net income	269,105				269,105
Dividends on common shares	(41,683)				(41,683)
Other comprehensive income (loss) during the period	$ 10,568						10,568
Balance at end of period (in shares) at Dec. 31, 2023	72,516,079		72,516,079
Balance at end of period at Dec. 31, 2023	$ 3,426,747		$ 72,516	1,945,385	1,539,957		(35,939)	$ (95,172)
Balance at end of period (in shares) at Dec. 31, 2023	3,462,738							3,462,738
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted shares (in shares)			130,520
Issuance of restricted shares	$ 0		$ 131	(131)
Issuance of common shares pursuant to PSU agreements (in shares)			63,301
Issuance of common shares pursuant to PSU agreements	0		$ 63	(63)
Forfeitures of restricted shares (in shares)			(10,655)
Forfeitures of restricted shares	(231)		$ (11)	(220)
Share-based compensation	13,671			13,671
Purchase of treasury shares (in shares)								167,898
Purchase of treasury shares	(7,956)							$ (7,956)
Net income	358,685				358,685
Dividends on common shares	(45,214)				(45,214)
Other comprehensive income (loss) during the period	$ 5,820						5,820
Balance at end of period (in shares) at Dec. 31, 2024	72,699,245		72,699,245
Balance at end of period at Dec. 31, 2024	$ 3,751,522		$ 72,699	$ 1,958,642	$ 1,853,428		$ (30,119)	$ (103,128)
Balance at end of period (in shares) at Dec. 31, 2024	3,630,636							3,630,636