Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 37,232	$ 38,252
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	3,087	2,982
Provision for credit loss expense	9,850	965
Securities premium amortization, net	7,239	6,132
Gain (loss) on sale of assets, net	(2,250)	83
Deferred federal income tax benefit	48	0
Change in loans held-for-sale	(13,445)	6,953
Change in other assets	(15,046)	7,927
Change in other liabilities	4,871	8,972
Total adjustments	(5,646)	34,014
Net cash provided by operating activities	31,586	72,266
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash received in acquisition of TB&T Bancshares, Inc.	61,028	0
Activity in available-for-sale securities:
Sales	95,437	231
Maturities	1,614,414	106,188
Purchases	(2,333,332)	(72,142)
Net increase in loans	1,012	(36,070)
Purchases of bank premises and equipment and other assets	(5,734)	(4,700)
Proceeds from sale of bank premises and equipment and other assets	171	65
Net cash used in investing activities	(567,004)	(6,428)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in noninterest-bearing deposits	(14,356)	49,638
Net increase in interest-bearing deposits	72,633	120,714
Net increase (decrease) in borrowings	476,515	(85,995)
Common stock transactions:
Proceeds from stock issuances	2,192	2,246
Dividends paid	(16,306)	(14,227)
Net cash provided by (used in) financing activities	520,678	72,376
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(14,740)	138,214
CASH AND CASH EQUIVALENTS, beginning of period	282,604	248,647
CASH AND CASH EQUIVALENTS, end of period	267,864	386,861
SUPPLEMENTAL INFORMATION AND NONCASH TRANSACTIONS:
Investment securities purchased but not yet settled	33,066	59,397
Investment Securities Sold But Not Yet Settled	126,119
Interest paid	$ 7,042	7,220
Transfer of loans and bank premises to other real estate		$ 237