Consolidated Statements of Shareholders' Equity (unaudited) - USD ($) $ in Thousands	Total		Common Stock and Related Surplus [Member]	Unearned ESOP Shares [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]
Beginning Balance at Dec. 31, 2018	$ 219,830		$ 80,431	$ (939)	$ 141,354	$ (1,016)
Comprehensive income:
Net income	23,718				23,718
Other comprehensive income	4,862					4,862
Stock Issued During Period, Value, Stock Options Exercised	7		7
Share-based compensation expense	430		430
Stock Issued During Period, Value, Employee Stock Ownership Plan	389		222	167
Stock Repurchased and Retired During Period, Value	(10,405)		(10,405)
Stock Issued During Period, Value, Acquisitions	8,918		8,918
Stock Issued During Period, Value, Dividend Reinvestment Plan	177		177
Common stock cash dividends declared	(5,504)				(5,504)
Ending Balance at Sep. 30, 2019	$ 242,422		79,780	(772)	159,568	3,846
Comprehensive income:
Stock Issued During Period, Shares, Employee Stock Ownership Plan	15,481
Common stock issuances from reinvested dividends, number of shares	6,781
Common Stock, Dividends, Per Share, Declared	$ 0.44
Stock Repurchased and Retired During Period, Shares	417,577
Stock Issued During Period, Shares, Acquisitions	465,931
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	17,255
Beginning Balance at Jun. 30, 2019	$ 235,701		80,946	(828)	153,362	2,221
Comprehensive income:
Net income	8,061				8,061
Other comprehensive income	1,625					1,625
Share-based compensation expense	149		149
Stock Issued During Period, Value, Employee Stock Ownership Plan	136		80	56
Stock Repurchased and Retired During Period, Value	(1,453)		(1,453)
Stock Issued During Period, Value, Dividend Reinvestment Plan	58		58
Common stock cash dividends declared	(1,855)				(1,855)
Ending Balance at Sep. 30, 2019	$ 242,422		79,780	(772)	159,568	3,846
Comprehensive income:
Stock Issued During Period, Shares, Employee Stock Ownership Plan	5,251
Common stock issuances from reinvested dividends, number of shares	2,227
Common Stock, Dividends, Per Share, Declared	$ 0.15
Stock Repurchased and Retired During Period, Shares	52,460
Beginning Balance at Dec. 31, 2019	$ 247,764	[1]	80,084	(714)	165,859	2,535
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect on Retained Earnings, Net of Tax (Deprecated 2020-01-31)	(6,756)
Cumulative Effect on Retained Earnings, Net of Tax (Deprecated 2020-01-31) | Accounting Standards Update 2016-13 [Member]							$ (6,756)
Comprehensive income:
Net income	21,075				21,075
Other comprehensive income	1,655					1,655
Stock Issued During Period, Value, Restricted Stock Award, Gross	0		0
Share-based compensation expense	402		402
Stock Issued During Period, Value, Employee Stock Ownership Plan	310		128	182
Stock Repurchased and Retired During Period, Value	(1,444)		(1,444)
Stock Issued During Period, Value, Acquisitions	15,354		15,354
Stock Issued During Period, Value, Dividend Reinvestment Plan	193		193
Common stock cash dividends declared	(6,590)				(6,590)
Ending Balance at Sep. 30, 2020	$ 271,963		94,717	(532)	173,588	4,190
Comprehensive income:
Stock Issued During Period, Shares, Employee Stock Ownership Plan	16,797
Common stock issuances from reinvested dividends, number of shares	11,758
Common Stock, Dividends, Per Share, Declared	$ 0.51
Stock Repurchased and Retired During Period, Shares	75,333
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	651
Stock Issued During Period, Shares, Acquisitions	570,000
Beginning Balance at Jun. 30, 2020	$ 263,431		94,539	(593)	166,163	3,322
Comprehensive income:
Net income	9,620				9,620
Other comprehensive income	868					868
Share-based compensation expense	79		79
Stock Issued During Period, Value, Employee Stock Ownership Plan	88		27	61
Stock Issued During Period, Value, Dividend Reinvestment Plan	72		72
Common stock cash dividends declared	(2,195)				(2,195)
Ending Balance at Sep. 30, 2020	$ 271,963		$ 94,717	$ (532)	$ 173,588	$ 4,190
Comprehensive income:
Stock Issued During Period, Shares, Employee Stock Ownership Plan	5,599
Common stock issuances from reinvested dividends, number of shares	4,771
Common Stock, Dividends, Per Share, Declared	$ 0.17

[1] Derived from audited consolidated financial statements