CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest incomeand divided income:
Loans	$ 719,153	$ 631,047	$ 602,998
Investment securities	72,893	58,547	59,546
Money martket investments and interest-bearing cash accounts	2,662	3,388	13,353
Total interest income and dividend income	794,708	692,982	675,897
Interest expense:
Deposits	41,482	68,388	77,782
Loans payable	0	21	0
Securities sold under agreements to repurchase	9,963	6,645	6,647
Advances from FHLB	8,199	11,251	14,963
Other borrowings	5,135	6,355	9,424
Total interest expense	64,779	92,660	108,816
Net interest income	729,929	600,322	567,081
Provision for credit losses - (benefit) expense:
Provision for Loan and Lease Losses	(61,720)	168,717	40,225
Provision for credit losses - (benefit) expense	(65,698)	170,985	39,813
Net interest income after provision for credit losses	795,627	429,337	527,268
Non-interest income:
Service charges and fees on deposit accounts	35,284	24,612	23,916
Mortgage banking activities	24,998	22,124	17,058
Net gain (loss) on sale of investments	0	13,198	(497)
Gain on early extinguishment of debt	0	94	0
Insurance commission income	11,945	9,364	10,186
Other non-interest income	48,937	41,834	39,909
Total non-interest income	121,164	111,226	90,572
Non-interest expenses:
Employees' compensation and benefits	200,457	177,073	162,374
Occupancy and equipment	93,253	74,633	63,169
Business promotion	15,359	12,145	15,710
Professional fees	59,956	52,633	45,889
Taxes, other than income taxes	22,151	17,762	15,325
Federal Deposit Insurance Corporation (FDIC) deposit insurance	6,544	6,488	6,319
Net (gain) loss on OREO and OREO expenses	(2,160)	3,598	14,644
Credit and debit card processing expenses	22,169	19,144	16,472
Communications	9,387	8,437	6,891
Merger and restructuring costs	26,435	26,509	11,442
Other non-interest expenses	35,423	25,818	20,233
Total non-interest expenses	488,974	424,240	378,468
Income before income taxes	427,817	116,323	239,372
Income tax expense	146,792	14,050	71,995
Net income	281,025	102,273	167,377
Net income attributable to common stockholders	$ 277,338	$ 99,597	$ 164,701
Net income per common share:
Basic	$ 1.32	$ 0.46	$ 0.76
Diluted	$ 1.31	$ 0.46	$ 0.76
Debt Securities [Member]
Provision for credit losses - (benefit) expense:
Provision for Other Credit Losses	$ (410)	$ 1,085	$ 0
Unfunded Loan Commitment [Member]
Provision for credit losses - (benefit) expense:
Provision for Other Credit Losses	$ (3,568)	$ 1,183	$ (412)