Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
OPERATING ACTIVITIES
Net income	$ 103,903	$ 92,549
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	23,954	24,230
Provision for credit losses	24,277	13,945
Loss on sale of investments	391	204
Net amortization (accretion) of investment securities and assets	6,295	(24,494)
Net amortization on borrowings	76	192
Stock-based compensation expense	8,018	8,164
Gain on sale of foreclosed assets and other real estate owned	(225)	(290)
Gain on sale of mortgage loans held for sale	(3,683)	(4,333)
Gain on sale of loans	0	(228)
Deferred income taxes	(335)	917
Income from bank owned life insurance	(6,716)	(5,269)
Originations of mortgage loans held for sale	(133,076)	(329,833)
Proceeds from sale of mortgage loans held for sale	129,903	356,085
Changes in assets and liabilities:
Interest receivable	(539)	(1,547)
Other assets	(1,548)	(10,064)
Accrued interest and other liabilities	27,658	57,874
Income taxes payable	(19,421)	(245)
Net cash provided by operating activities	158,932	177,857
INVESTING ACTIVITIES
Net change in loans	(698,580)	(835,002)
Proceeds from sale of loans	6,657	15,556
Net change in due from banks - time	250	347
Purchases of premises and equipment, net	(18,718)	(17,000)
Proceeds from sale of foreclosed assets and other real estate owned	1,477	2,819
Proceeds from maturities of available-for-sale securities	296,256	762,094
Purchases of available-for-sale securities	(1,526)	(259,586)
Proceeds from maturities of held-to-maturity securities	36,583	30,848
Purchases of held-to-maturity securities	(45,921)	(329,660)
Proceeds from bank owned life insurance death benefits	3,686	0
Purchase of Spirit of Texas Bancshares, Inc.	0	276,396
Net cash used in investing activities	(419,836)	(353,188)
FINANCING ACTIVITIES
Net change in deposits	(59,003)	(49,701)
Dividends paid on common stock	(50,835)	(45,844)
Net change in other borrowed funds	514,043	(315,778)
Net change in federal funds purchased and securities sold under agreements to repurchase	(57,817)	(30,302)
Net shares cancelled under stock compensation plans	(2,505)	(3,905)
Shares issued under employee stock purchase plan	833	1,151
Repurchases of common stock	(20,022)	(66,096)
Net cash provided by (used in) financing activities	324,694	(510,475)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	63,790	(685,806)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	682,122	1,650,653
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 745,912	$ 964,847