Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 52,568,000	$ 55,972,000
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	3,074,000	3,231,000
PROVISION FOR CREDIT LOSSES	2,781,000	4,782,000
Securities premium amortization, net	13,770,000	19,836,000
Discount accretion on purchased loans	0	(373,000)
Gain on sale of securities and other assets, net	(976,000)	(1,074,000)
Change in loans held-for-sale	48,000	9,367,000
Change in other assets	16,774,000	9,434,000
Change in other liabilities	7,848,000	(14,490,000)
Total adjustments	43,319,000	30,713,000
Net cash provided by operating activities	95,887,000	86,685,000
Activity in available-for-sale securities:
Sales	145,948,000	0
Maturities	116,922,000	211,266,000
Purchases	(3,298,000)	(551,559,000)
Net increase in loans held-for-investment	(133,974,000)	(176,350,000)
Purchases of bank premises and equipment	(6,347,000)	(3,193,000)
Proceeds from sale of bank premises and equipment and other assets	2,423,000	0
Net cash provided by (used in) investing activities	121,674,000	(519,836,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in noninterest-bearing deposits	(170,797,000)	198,494,000
Net increase in interest-bearing deposits	101,708,000	234,843,000
Net change in borrowings	(9,581,000)	87,443,000
Common stock transactions:
Proceeds from stock option exercises	913,000	2,921,000
Dividends paid	(24,271,000)	(21,385,000)
Net cash provided by (used in) financing activities	(102,028,000)	502,316,000
NET INCREASE IN CASH AND CASH EQUIVALENTS	115,533,000	69,165,000
CASH AND CASH EQUIVALENTS, beginning of period	330,678,000	528,588,000
CASH AND CASH EQUIVALENTS, end of period	446,211,000	597,753,000
SUPPLEMENTAL INFORMATION AND NONCASH TRANSACTIONS:
Interest paid	22,726,000	1,523,000
Transfer of loans to other real estate	175,000	0
Restricted stock grant (forfeiture)	$ 479,000	$ 559,000