Consolidated Statements of Shareholders’ Equity (unaudited) - USD ($) $ in Thousands	Total	Cumulative effect of change in accounting principle for ASU 2022-02	Common Stock	Capital Surplus	Retained Earnings	Retained Earnings Cumulative effect of change in accounting principle for ASU 2022-02	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 (in shares) at Dec. 31, 2021								2,407,898
Balance at beginning of period at Dec. 31, 2021	$ 2,966,451		$ 72,017	$ 1,924,813	$ 1,006,436		$ 15,590	$ (52,405)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted shares (in shares)			145,393
Issuance of restricted shares	1,341		$ 145	1,196
Proceeds from exercise of stock options (in shares)			49,803
Proceeds from exercise of stock options	1,445		$ 50	1,395
Share-based compensation	1,298			1,298
Purchase of treasury shares (in shares)								365,340
Purchase of treasury shares	(17,234)							$ (17,234)
Net income	81,698				81,698
Dividends on common shares	(10,409)				(10,409)
Other comprehensive loss during the period	(17,431)						(17,431)
Balance at end of period (in shares) at Mar. 31, 2022			72,212,322
Balance at end of period (in shares) at Mar. 31, 2022								2,773,238
Balance at end of period at Mar. 31, 2022	3,007,159		$ 72,212	1,928,702	1,077,725		(1,841)	$ (69,639)
Balance at beginning of period (in shares) at Dec. 31, 2021			72,017,126
Balance at beginning of period (in shares) at Dec. 31, 2021								2,407,898
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 end of period (in shares) at Dec. 31, 2022			72,263,727
Balance at end of period (in shares) at Dec. 31, 2022	2,894,677							2,894,677
Balance at end of period at Dec. 31, 2022	$ 3,197,400	$ 1,277	$ 72,264	1,935,211	1,311,258	$ 1,277	(46,507)	$ (74,826)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-02 [Member]
Issuance of restricted shares (in shares)			101,510
Issuance of restricted shares	$ 0		$ 101	(101)
Issuance of common shares pursuant to PSU agreements (in shares)			102,973
Issuance of common shares pursuant to PSU agreements	0		$ 103	(103)
Proceeds from exercise of stock options (in shares)			16,000
Proceeds from exercise of stock options	476		$ 16	460
Share-based compensation	2,197			2,197
Purchase of treasury shares (in shares)								215,670
Purchase of treasury shares	(9,058)							$ (9,058)
Net income	60,421				60,421
Dividends on common shares	(10,444)				(10,444)
Other comprehensive loss during the period	$ 10,926						10,926
Balance at end of period (in shares) at Mar. 31, 2023			72,484,210
Balance at end of period (in shares) at Mar. 31, 2023	3,110,347							3,110,347
Balance at end of period at Mar. 31, 2023	$ 3,253,195		$ 72,484	$ 1,937,664	$ 1,362,512		$ (35,581)	$ (83,884)