CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income			$ 42,311	$ 41,517
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation			4,006	3,889
Provision for loan/lease losses	$ 20,342	$ 2,012	48,624	6,087
Stock-based compensation expense			1,536	1,869
Deferred compensation expense accrued			2,660	2,087
Losses (gains) on other real estate owned, net			(298)	3,205
Amortization of premiums on securities, net			728	1,339
Caplet amortization			383
Securities (gains) losses, net			(1,867)	56
Loans originated for sale			(172,282)	(104,824)
Proceeds on sales of loans			170,362	97,916
Gains on sales of residential real estate loans	(1,370)	(890)	(3,218)	(1,748)
Gains on sales of government guaranteed portions of loans		(519)		(589)
Loss on liability extinguishment, net	1,874	148	2,450	148
Gains on sales of premises and equipment			(13)	(67)
Amortization of intangibles	531	560	1,628	1,706
Accretion of acquisition fair value adjustments, net			(2,194)	(3,413)
Increase in cash value of bank-owned life insurance			(1,443)	(1,441)
Loss on sale of subsidiary	305		305
Goodwill impairment			500
Increase in other assets			(8,351)	(1,953)
Decrease in other liabilities			43,489	336
Net cash provided by operating activities			129,316	46,120
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease in federal funds sold			9,270	17,098
Net increase in interest-bearing deposits at financial institutions			(154,247)	(57,180)
Proceeds from sales of other real estate owned			4,353	840
Activity in securities portfolio:
Purchases			(255,500)	(28,119)
Calls, maturities and redemptions			38,461	9,074
Paydowns			33,870	36,649
Sales			28,579	33,128
Activity in restricted investment securities:
Purchases			(4,600)	(5,682)
Redemptions			8,843	5,006
Proceeds from the liquidation of bank-owned life insurance			10,999
Net increase in loans/leases originated and held for investment			(555,315)	(237,286)
Purchase of premises and equipment			(2,250)	(8,755)
Proceeds from sales of premises and equipment			94	146
Net cash transfered in sale of subsidiary			349
Net cash (used in) investing activities			(837,792)	(235,081)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposit accounts			731,374	276,960
Net increase (decrease) in short-term borrowings			17,007	(9,091)
Activity in Federal Home Loan Bank advances:
Term advances			125,000	25,000
Calls and maturities			(81,600)	(35,000)
Net change in short-term and overnight advances			(109,300)	(15,965)
Prepayments			(55,274)	(30,228)
Activity in other borrowings:
Calls, maturities and scheduled principal payments				(11,937)
Prepayments				(46,313)
Paydown of revolving line of credit				(9,000)
Prepayments on brokered and public time deposits			29,359
Proceeds from subordinated notes			50,000	63,393
Payment of cash dividends on common stock			(2,831)	(2,822)
Proceeds from issuance of common stock, net			1,199	1,143
Repurchase and cancellation of shares			(3,780)
Net cash provided by financing activities			701,154	206,140
Net increase in cash and due from banks			(7,322)	17,179
Cash and due from banks, beginning			76,254	85,523	$ 85,523
Cash and due from banks, ending	68,932	$ 102,702	68,932	102,702	76,254
Supplemental disclosure of cash flow information, cash payments (receipts) for:
Interest			26,920	45,826
Income/franchise taxes			16,713	(769)
Supplemental schedule of noncash investing activities:
Change in accumulated other comprehensive income, unrealized gains on securities available for sale and derivative instruments, net			(683)	5,130
Exchange of shares of common stock in connection with payroll taxes for restricted stock and in connection with stock options exercised			(491)	(189)
Transfers of loans to other real estate owned			51	1,049
Due to broker for purchases of securities			8,550
Increase in the fair value of back-to-back interest rate swap assets and liabilities			151,398	80,760
Dividends payable			945	$ 944
Consideration received	1,328		1,328
Assets Sold:
Total assets sold					11,966
Liabilities Sold:
Total liabilities sold					$ 5,003
Net assets sold	1,633		1,633
Loss on sale of the Bates Companies:	(305)		(305)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Bates Companies [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on sale of subsidiary			305
Supplemental schedule of noncash investing activities:
Consideration received	448		448
Assets Sold:
Cash and due from banks	349		349
Premises and equipment, net	19		19
Other assets	2,211		2,211
Total assets sold	2,579		2,579
Liabilities Sold:
Other liabilities	946		946
Total liabilities sold	$ 946		946
Forgiveness of earn-out consideration			880
Loss on sale of the Bates Companies:			$ (305)