Condensed Financial Information - Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
NET EARNINGS		$ 223,511	$ 198,977	$ 234,475
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization, net		13,427	12,578	12,762
Decrease in other assets		(7,122)	(3,895)	(1,281)
Increase (decrease) in other liabilities		11,177	6,663	(29,577)
Cash flows from investing activities:
Purchases of bank premises and equipment and software		(16,720)	(17,251)	(15,784)
Cash flows from financing activities:
Cash dividends paid		(102,913)	(99,965)	(91,315)
Repurchase of stock		0	(2,736)	(9,449)
Net increase (decrease) in cash and cash equivalents		226,822	205,913	(197,910)
Cash and cash equivalents, beginning of year		536,591
Cash and cash equivalents, end of year		763,413	536,591
Parent Company [Member]
Cash flows from operating activities:
NET EARNINGS		223,511	198,977	234,475
Adjustments to reconcile net earnings to net cash provided by operating activities:
Excess of earnings over dividends of subsidiaries (1)	[1]	(177,467)	(72,444)	(174,741)
Depreciation and amortization, net		166	116	188
Decrease in other assets		2,033	698	645
Increase (decrease) in other liabilities		3,494	(2,721)	933
Other		0	2	0
Net cash provided by operating activities		51,737	124,628	61,500
Cash flows from investing activities:
Purchases of bank premises and equipment and software		(717)	0	(385)
Net cash provided by (used in) investing activities		(717)	0	(385)
Cash flows from financing activities:
Proceeds from stock option exercises		3,160	2,132	6,545
Cash dividends paid		(102,913)	(99,965)	(91,315)
Repurchase of stock		0	(2,735)	(9,449)
Net cash used in financing activities		(99,753)	(100,568)	(94,219)
Net increase (decrease) in cash and cash equivalents		(48,733)	24,060	(33,104)
Cash and cash equivalents, beginning of year		143,319	119,259	152,363
Cash and cash equivalents, end of year		$ 94,586	$ 143,319	$ 119,259

[1] Eliminates in consolidation