Condensed Financial Information (Parent Company Only) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
OPERATING ACTIVITIES
Net income	$ 152,693	$ 175,057	$ 256,412
Items not requiring (providing) cash
Stock-based compensation expense	11,290	12,189	15,317
Deferred income taxes	(2,782)	(2,460)	14,933
Changes in:
Other assets	101,288	263,969	(7,214)
Net cash provided by operating activities	425,924	540,979	322,198
INVESTING ACTIVITIES
Net cash provided by (used in) investing activities	369,507	(183,593)	(946,233)
FINANCING ACTIVITIES
Stock repurchases	0	(40,322)	(111,133)
Dividends paid on common stock	(105,439)	(100,962)	(94,096)
Net cash used in financing activities	(722,146)	(425,416)	(344,496)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	73,285	(68,030)	(968,531)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	614,092	682,122	1,650,653
CASH AND CASH EQUIVALENTS, END OF YEAR	687,377	614,092	682,122
Parent Company
OPERATING ACTIVITIES
Net income	152,693	175,057	256,412
Items not requiring (providing) cash
Stock-based compensation expense	11,290	12,189	15,317
Depreciation and amortization	1,614	1,637	1,981
Deferred income taxes	(1,628)	(1,742)	(652)
Equity in undistributed net income (loss) of bank subsidiaries	76,061	(41,775)	(72,778)
Changes in:
Other assets	(23,437)	37,720	(26,775)
Other liabilities	12,734	2,293	(28,745)
Net cash provided by operating activities	229,327	185,379	144,760
INVESTING ACTIVITIES
Net collections of loans	102
Net collections of loans		1,310	1,198
Net purchases of premises and equipment	(45)	(52)	(21)
Cash paid in business combinations	0	0
Cash acquired in business combinations			60,126
Other, net	24	5,856	1,688
Net cash provided by (used in) investing activities	81	7,114	62,991
FINANCING ACTIVITIES
Repayment of long-term debt, net	(1,717)	(1,664)	(57,436)
Issuance of common stock, net	375
Cancellation of common stock, net		(2,021)	(3,882)
Stock repurchases	0	(40,322)	(111,133)
Dividends paid on common stock	(105,439)	(100,962)	(94,096)
Net cash used in financing activities	(106,781)	(144,969)	(266,547)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	122,627	47,524	(58,796)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	164,439	116,915	175,711
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 287,066	$ 164,439	$ 116,915