Parent Only Condensed Financial Statements - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 20,347	$ 21,443	$ 21,289
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Stock-based compensation	470	555	482
Benefit for deferred income taxes	(1,051)	(589)	403
Net cash provided by operating activities	16,990	21,721	29,911
Cash flows from financing activities:
Cash dividend payments on common stock	(5,530)	(5,805)	(4,270)
Purchase and retirement of common stock	11,052	15,619	894
Proceeds from exercise of stock options	279	276	738
Net cash (used in) provided by financing activities	373,321	20,055	(137,602)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	52,574
CASH AND CASH EQUIVALENTS AT END OF YEAR	70,278	52,574
Non-cash investing and financing activities:
Proceeds from stock issued under employee stock purchase plan	199	216	211
Parent Company
Cash flows from operating activities:
Net income	20,347	21,443	21,289
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Undistributed net income of subsidiary, net of distributions	(5,328)	(1,932)	(19,075)
Stock-based compensation	470	555	482
Net (increase) decrease in other assets	(208)	136	372
Net increase (decrease) in other liabilities	(31)	69	166
Benefit for deferred income taxes	75	10	11
Net cash provided by operating activities	15,325	20,281	3,245
Cash flows used in investing activities:
Investment in subsidiary	0	0	0
Cash flows from financing activities:
Cash dividend payments on common stock	(5,530)	(5,805)	(4,270)
Purchase and retirement of common stock	11,052	15,619	894
Proceeds from exercise of stock options	279	276	738
Net cash (used in) provided by financing activities	(16,104)	(20,932)	(4,215)
Increase (decrease) in cash and cash equivalents	(779)	(651)	(970)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	1,675	2,326	3,296
CASH AND CASH EQUIVALENTS AT END OF YEAR	896	1,675	2,326
Cash paid during the year for interest	153	215	185
Non-cash investing and financing activities:
Proceeds from stock issued under employee stock purchase plan	$ 199	$ 216	$ 211