Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Jul. 30, 2024	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Dividends declared (in dollars per share)		$ 0.55	$ 0.54	$ 1.10	$ 1.08
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period				$ (599,100)	$ (836,955)
Net change in unrealized gain (loss)		$ (5,943)	$ (160,408)	(77,749)	(36,363)
Interest revenue, Investment securities		12,027	16,033	24,210	32,084
Loss (gain) on available for sale securities, net		(34)	3,010	45,137	3,010
Other comprehensive income, before income taxes		6,050	(141,365)	(8,402)	(1,269)
Federal and state income taxes		1,424	(33,247)	(2,000)	(1,552)
Other comprehensive income, net of income taxes		4,626	(108,118)	(6,402)	283
Balance, End of Period		(605,502)	(836,672)	(605,502)	(836,672)
Accumulated Net Unrealized Gain (Loss) on Available for Sale Securities [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period				(473,212)	(664,618)
Net change in unrealized gain (loss)				(77,749)	(36,363)
Interest revenue, Investment securities				0	0
Loss (gain) on available for sale securities, net				45,137	3,010
Other comprehensive income, before income taxes				(32,612)	(33,353)
Federal and state income taxes				(7,695)	(8,839)
Other comprehensive income, net of income taxes				(24,917)	(24,514)
Balance, End of Period		(498,129)	(689,132)	(498,129)	(689,132)
AOCI, Accumulated Gain (Loss), Debt Securities, Investment Securities Transferred from Available-for-sale, Parent
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period				(125,888)	(172,337)
Net change in unrealized gain (loss)				0	0
Interest revenue, Investment securities				24,210	32,084
Loss (gain) on available for sale securities, net				0	0
Other comprehensive income, before income taxes				24,210	32,084
Federal and state income taxes				5,695	7,287
Other comprehensive income, net of income taxes				18,515	24,797
Balance, End of Period		$ (107,373)	$ (147,540)	$ (107,373)	$ (147,540)
Subsequent Event [Member]
Dividends Payable, Date Declared	Jul. 30, 2024
Dividends declared (in dollars per share)	$ 0.55
Dividends Payable, Date to be Paid	Aug. 30, 2024
Dividends Payable, Date of Record	Aug. 15, 2024