Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest income:
Interest and fees on loans	$ 110,447	$ 88,805	$ 91,671
Interest on securities -- taxable	1,004	1,219	2,258
Interest on securities -- tax-exempt	1,785	2,497	2,828
Interest on deposits in banks	800	2,447	1,537
Total interest income	114,036	94,968	98,294
Interest expense:
Interest on deposits	5,460	5,392	5,144
Interest on short-term borrowings	4	123	811
Interest on long-term debt	0	0	1,494
Total interest expense	5,464	5,515	7,449
Net interest income	108,572	89,453	90,845
Provision for loan losses	12,668	3,571	2,393
Net interest income after provision for loan losses	95,904	85,882	88,452
Noninterest income:
Insurance commissions	0	0	966
Net gain (loss) on sale of securities	385	(43)	(618)
Net FDIC indemnification asset amortization	(1,690)	(2,377)	(2,181)
Litigation settlements	0	6,995	0
Other operating income	4,369	2,804	2,548
Total noninterest income	29,833	33,677	26,443
Noninterest expense:
Salaries and employee benefits	44,005	37,148	36,690
Occupancy expense	5,043	4,334	4,542
Furniture and equipment expense	5,558	4,457	3,980
Service fees	5,665	4,448	3,860
Advertising and public relations	1,951	2,310	2,011
Professional fees	1,224	1,698	1,430
Amortization of intangibles	1,450	997	1,039
FDIC premiums and assessments	426	318	906
Loss on extinguishment of debt	0	0	1,096
Goodwill impairment	0	0	1,492
Merger expense	1,893	2,124	0
Other operating expense	12,410	11,929	12,727
Total noninterest expense	79,625	69,763	69,773
Income before income taxes	46,112	49,796	45,122
Income tax expense	10,186	10,994	8,782
Net income	$ 35,926	$ 38,802	$ 36,340
Earnings per common share
Basic (in dollars per share)	$ 2.02	$ 2.47	$ 2.19
Diluted (in dollars per share)	2.02	2.46	2.18
Cash dividends per common share (in dollars per share)	$ 1.00	$ 0.96	$ 0.78
Weighted average shares outstanding
Basic (in shares)	17,781,748	15,690,812	16,587,504
Diluted (in shares)	17,815,380	15,756,093	16,666,385
Common Dividend [Member]
Earnings per common share
Cash dividends per common share (in dollars per share)	$ 1.00	$ 0.96	$ 0.78
Special Cash Dividend [Member]
Earnings per common share
Cash dividends per common share (in dollars per share)	$ 0	$ 0	$ 0.48
Fiduciary and Trust [Member]
Noninterest income:
Noninterest income	$ 3,417	$ 3,423	$ 3,262
Deposit Account [Member]
Noninterest income:
Noninterest income	13,019	14,594	14,733
Financial Service, Other [Member]
Noninterest income:
Noninterest income	$ 10,333	$ 8,281	$ 7,733