CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income			$ 57,408,000	$ 43,120,000	$ 35,707,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation			5,225,000	4,451,000	3,949,000
Provision for loan/lease losses	$ 979,000	$ 1,612,000	7,066,000	12,658,000	8,470,000
Deferred income taxes			6,364,000	6,292,000	(6,030,000)
Stock-based compensation expense			2,469,000	1,443,000	1,187,000
Deferred compensation expense accrued			2,773,000	1,824,000	1,426,000
Losses on other real estate owned, net			3,361,000	2,585,000	(151,000)
Amortization of premiums on securities, net			1,561,000	1,614,000	1,839,000
Securities losses, net			30,000		88,000
Loans originated for sale			(151,692,000)	(57,698,000)	(49,579,000)
Proceeds on sales of loans			152,633,000	58,353,000	51,642,000
Gains on sales of residential real estate loans			(2,571,000)	(901,000)	(409,000)
Gains on sales of government guaranteed portions of loans			(748,000)	(405,000)	(1,164,000)
Loss on debt extinguishment, net			436,000
Gains on sales of premises and equipment			753,000
Amortization of intangibles			2,266,000	1,692,000	1,001,000
Accretion of acquisition fair value adjustments, net			(4,344,000)	(5,527,000)	(4,941,000)
Increase in cash value of bank-owned life insurance			(1,973,000)	(1,632,000)	(1,802,000)
Gain on sale of assets and liabilities of subsidiary			(12,286,000)
Goodwill impairment			3,000,000
Decrease (increase) in other assets			(19,152,000)	(11,137,000)	726,000
Increase (decrease) in other liabilities			23,915,000	7,539,000	(8,246,000)
Net cash provided by operating activities			76,494,000	64,271,000	33,713,000
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease (increase) in federal funds sold			16,598,000	3,799,000	(7,940,000)
Net decrease (increase) in interest-bearing deposits at financial institutions			(69,984,000)	(14,508,000)	12,138,000
Proceeds from sales of other real estate owned			840,000	2,539,000	1,138,000
Activity in securities portfolio:
Purchases			(71,963,000)	(84,045,000)	(179,786,000)
Calls, maturities and redemptions			25,193,000	23,931,000	43,010,000
Paydowns			50,830,000	44,287,000	38,496,000
Sales			30,055,000	1,938,000	71,092,000
Activity in restricted investment securities:
Purchases			(5,859,000)	(5,409,000)	(4,824,000)
Redemptions			7,621,000	3,157,000	515,000
Net increase in loans/leases originated and held for investment			(320,368,000)	(292,697,000)	(375,226,000)
Purchase of premises and equipment			(12,429,000)	(11,457,000)	(5,761,000)
Proceeds from sales of premises and equipment			2,562,000
Purchase of interest rate caps			(4,347,000)
Net cash received for sale of assets and liabilities of subsidiary			42,587,000
Net cash paid for acquisition				(5,183,000)	(3,369,000)
Net cash (used in) investing activities			(308,664,000)	(333,648,000)	(410,517,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposit accounts			335,580,000	271,266,000	385,082,000
Net increase (decrease) in short-term borrowings			(14,193,000)	13,638,000	(39,080,000)
Activity in Federal Home Loan Bank advances:
Term advances			25,000,000	15,080,000	1,600,000
Calls and maturities			(35,000,000)	(40,000,000)	(8,000,000)
Net change in short-term and overnight advances			(52,465,000)	24,765,000	60,900,000
Prepayments			(30,323,000)		(4,108,000)
Activity in other borrowings:
Proceeds from other borrowings				9,000,000	7,000,000
Calls, maturities and scheduled principal payments			(11,937,000)	(12,550,000)	(21,000,000)
Prepayments			(46,313,000)
Paydown of revolving line of credit			(9,000,000)
Proceeds from subordinated notes			63,393,000
Payment of cash dividends on common stock			(3,767,000)	(3,300,000)	(2,494,000)
Proceeds from issuance of common stock, net			1,926,000	1,279,000	2,056,000
Net cash provided by financing activities			222,901,000	279,178,000	381,956,000
Net increase (decrease) in cash and due from banks			(9,269,000)	9,801,000	5,152,000
Cash and due from banks, beginning			85,523,000	75,722,000	70,570,000
Cash and due from banks, ending	76,254,000	85,523,000	76,254,000	85,523,000	75,722,000
Cash and due from banks	76,254,000	85,523,000	76,254,000	85,523,000
Supplemental disclosure of cash flow information, cash payments (receipts) for:
Interest			59,292,000	38,782,000	19,054,000
Income/franchise taxes			2,719,000	30,000	13,040,000
Supplemental schedule of noncash investing activities:
Change in accumulated other comprehensive income, unrealized gains on securities available for sale and derivative instruments, net			4,446,000	(3,206,000)	1,092,000
Exchange of shares of common stock in connection with payroll taxes for restricted stock and in connection with stock options exercised			(218,000)	(877,000)	(1,010,000)
Transfers of loans to other real estate owned			1,086,000	943,000	9,023,000
Increase (decrease) in the fair value of back-to-back interest rate swap assets and liabilities			62,483,000	17,798,000	2,059,000
Dividends payable			947,000	939,000	693,000
Transfer of equity securities from securities available for sale to other assets at fair value				2,614,000
Assets Sold:
Total assets sold	11,966,000		11,966,000
Liabilities Sold:
Total liabilities sold	5,003,000		5,003,000
Gain on sale of certain assets and certain liabilities of RB&T:			12,286,000
Fair value of assets acquired:
Cash and due from banks		4,651,000		4,651,000	4,435,000
Interest-bearing deposits at financial institutions		62,924,000		62,924,000	3,954,000
Securities available for sale, at fair value		4,845,000		4,845,000	49,703,000
Loans/leases receivable held for investment, net		477,337,000		477,337,000	192,518,000
Bank-owned life insurance		7,092,000		7,092,000
Premises and equipment, net		6,092,000		6,092,000	4,808,000
Restricted investment securities		3,654,000		3,654,000	477,000
Intangibles		10,064,000		10,064,000	2,698,000
Other assets		2,255,000		2,255,000	998,000
Total assets sold		578,914,000		578,914,000	259,591,000
Fair value of liabilities assumed:
Deposits		439,579,000		439,579,000	212,468,000
Short-term borrowings		1,143,000		1,143,000	13,102,000
FHLB advances		74,540,000		74,540,000	4,108,000
Other borrowings		9,544,000		9,544,000
Junior subordinated debentures					3,857,000
Other liabilities		8,878,000		8,878,000	2,596,000
Total liabilities assumed		533,684,000		533,684,000	236,131,000
Net assets acquired		$ 45,230,000		45,230,000	23,460,000
Consideration paid:
Cash paid				9,834,000	7,803,000
Promissory note				1,500,000
Contingent commitment				2,000,000
Common stock				81,637,000	30,880,000
Total consideration paid				94,971,000	38,683,000
Goodwill				49,741,000	15,223,000
RB&T
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of assets and liabilities of subsidiary			(12,286,000)
Activity in restricted investment securities:
Net cash received for sale of assets and liabilities of subsidiary			42,587,000
Supplemental schedule of noncash investing activities:
Cash proceeds	46,560,000		46,560,000
Assets Sold:
Cash and due from banks	3,973,000		3,973,000
Interest-bearing deposits at financial institutions	55,291,000		55,291,000
Securities held to maturity, at amortized cost	3,243,000		3,243,000
Securities available for sale, at fair value	21,874,000		21,874,000
Loans/leases receivable held for investment, net	357,931,000		357,931,000
Premises and equipment, net	5,612,000		5,612,000
Restricted investment securities	675,000		675,000
Other real estate owned, net	2,134,000		2,134,000
Other assets	3,228,000		3,228,000
Total assets sold	453,961,000		453,961,000
Liabilities Sold:
Noninterest-bearing deposits	69,802,000		69,802,000
Interest-bearing deposits	331,486,000		331,486,000
Short-term borrowings	1,158,000		1,158,000
Federal Home Loan Bank advances	15,000,000		15,000,000
Other liabilities	2,241,000		2,241,000
Total liabilities sold	$ 419,687,000		419,687,000
Gain on sale of certain assets and certain liabilities of RB&T:			12,286,000
Springfield Bancshares
Consideration paid:
Cash paid				3,747,209
Goodwill				45,975,000
Guaranty Bank [Member]
Consideration paid:
Cash paid					3,368,909
Goodwill					$ 15,223,000
Bates Companies [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Goodwill impairment			$ 3,000,000
Consideration paid:
Cash paid				1,435,595
Goodwill				$ 3,766,000