Condensed Financial Statements of Parent Company - Condensed Financial Statements of Parent Company (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	$ 13,127	$ 16,757	$ 14,253
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Other assets	553	189	469
Net cash from operating activities	(4,956)	18,785	30,605
Cash flows from investing activities
Net cash from investing activities	(147,068)	(118,031)	(146,282)
Cash flows from financing activities
Repurchase of common stock	(8,104)	(5,391)
Cash dividend paid on common stock	(4,262)	(3,151)
Net cash from financing activities	172,393	107,556	130,153
Net change in cash and cash equivalents	20,369	8,310	14,476
Cash and cash equivalents at beginning of period	86,036	77,726	63,250
Cash and cash equivalents at end of period	106,405	86,036	77,726
Parent Company
Cash flows from operating activities
Net income	13,127	16,757	14,253
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Equity in undistributed subsidiary income	(13,899)	(17,480)	(14,347)
Other assets	107	6	$ 94
Change in accounts payable and other liabilities	359	88
Net cash from operating activities	(306)	(629)
Cash flows from financing activities
Repurchase of common stock	(8,104)	(5,391)
Cash dividend paid on common stock	(4,262)	(3,151)
Proceeds from subsidiaries	13,921	11,390
Net cash from financing activities	1,555	2,848
Net change in cash and cash equivalents	1,249	2,219
Cash and cash equivalents at beginning of period	2,219
Cash and cash equivalents at end of period	$ 3,468	$ 2,219