Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
INTEREST INCOME:
Interest and fees on loans	$ 65,932	$ 55,740	$ 128,927	$ 108,971
Interest on investment securities:
Taxable	14,029	13,925	28,684	27,213
Exempt from federal income tax	12,149	9,244	21,844	19,007
Interest on federal funds sold and interest-bearing deposits in banks	87	667	842	1,286
Total interest income	92,197	79,576	180,297	156,477
INTEREST EXPENSE:
Interest on deposits	2,550	7,286	9,230	13,947
Other	412	675	929	1,401
Total interest expense	2,962	7,961	10,159	15,348
Net interest income	89,235	71,615	170,138	141,129
PROVISION FOR LOAN LOSSES	8,700	600	18,550	1,565
Net interest income after provision for loan losses	80,535	71,015	151,588	139,564
NONINTEREST INCOME:
Trust fees	6,961	7,027	14,398	14,006
Service charges on deposit accounts	4,318	5,374	10,233	10,550
ATM, interchange and credit card fees	8,049	7,352	15,449	14,192
Gain on sale and fees on mortgage loans	13,676	4,721	17,528	8,195
Net gain on sale of available-for-sale securities (includes $1,512 and $676 for the three months ended June 30, 2020 and 2019, respectively, and $3,574 and $676 for the six months ended June 30, 2020 and 2019, respectively, related to accumulated other comprehensive earnings reclassifications)	1,512	676	3,574	676
Net gain on sale of foreclosed assets	52	53	53	122
Net gain (loss) on sale of assets	(24)	6	92	6
Interest on loan recoveries	154	903	419	1,241
Other	2,221	1,864	3,905	3,425
Total noninterest income	36,919	27,976	65,651	52,413
NONINTEREST EXPENSE:
Salaries, commissions and employee benefits	30,814	27,394	60,456	53,918
Loss from partial settlement of pension plan	0	0	0	900
Net occupancy expense	3,101	2,779	6,128	5,542
Equipment expense	2,010	2,331	4,085	4,784
FDIC insurance premiums	463	538	508	1,076
ATM, interchange and credit card expenses	2,610	2,427	5,595	4,810
Professional and service fees	2,497	1,987	5,090	3,820
Printing, stationery and supplies	533	502	1,099	868
Operational and other losses	728	480	1,304	746
Software amortization and expense	2,010	1,783	4,034	3,380
Amortization of intangible assets	508	264	1,017	532
Other	8,047	7,819	19,324	15,297
Total noninterest expense	53,321	48,304	108,640	95,673
EARNINGS BEFORE INCOME TAXES	64,133	50,687	108,599	96,304
INCOME TAX EXPENSE (includes $318 and $142 for the three months ended June 30, 2020 and 2019, respectively, and $751 and $142 for the six months ended June 30, 2020 and 2019, respectively, related to income tax expense from reclassification items)	10,663	8,594	17,898	15,959
NET EARNINGS	$ 53,470	$ 42,093	$ 90,701	$ 80,345
EARNINGS PER SHARE, BASIC	$ 0.38	$ 0.31	$ 0.64	$ 0.59
EARNINGS PER SHARE, DILUTED	0.38	0.31	0.64	0.59
DIVIDENDS PER SHARE	$ 0.13	$ 0.12	$ 0.25	$ 0.23