Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 113,297	$ 90,701
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	6,407	5,935
Provision for credit losses	(3,203)	18,550
Securities premium amortization, net	30,288	17,018
Discount accretion on purchased loans	(1,181)	(1,376)
Gain on sale of assets, net	(1,088)	(3,719)
Deferred federal income tax (expense) benefit	814	(407)
Change in loans held-for-sale	20,899	(36,018)
Change in other assets	(4,125)	(16,452)
Change in other liabilities	(13,792)	38,274
Total adjustments	35,019	21,805
Net cash provided by operating activities	148,316	112,506
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash received in acquisition of TB&T Bancshares, Inc.		61,028
Activity in available-for-sale securities:
Sales	10,631	252,958
Maturities	8,037,370	5,654,371
Purchases	(9,130,287)	(6,392,611)
Net increase in loans held-for-investment	(130,765)	(613,201)
Purchases of bank premises and equipment	(11,640)	(7,681)
Proceeds from sale of bank premises and equipment and other assets	494	1,144
Net cash used in investing activities	(1,224,197)	(1,043,992)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in noninterest-bearing deposits	444,341	638,726
Net increase in interest-bearing deposits	661,536	365,985
Net increase in borrowings	119,876	67,868
Common stock transactions:
Proceeds from stock option exercises	2,618	2,481
Dividends paid	(36,982)	(33,371)
Repurchase of stock		(8,008)
Net cash provided by financing activities	1,191,389	1,033,681
NET INCREASE IN CASH AND CASH EQUIVALENTS	115,508	102,195
CASH AND CASH EQUIVALENTS, beginning of period	729,084	282,604
CASH AND CASH EQUIVALENTS, end of period	844,592	384,799
SUPPLEMENTAL INFORMATION AND NONCASH TRANSACTIONS:
Interest paid	3,500	10,246
Federal income taxes paid	19,263
Transfer of loans and bank premises to other real estate	283	45
Investment securities purchased but not settled	189,838	33,553
Restricted stock grant (forfeiture)	$ (663)	913
Stock issued in acquisition of TB&T Bancshares, Inc.		$ 220,273