Condensed Financial Statements of Parent Company, Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities [Abstract]
Net income (loss)	$ (29)	$ 3,797	$ 3,634
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Stock compensation expense	17	0	0
Increase (decrease) in other assets	458	(567)	(3,969)
Increase (decrease) in other liabilities	3,177	(243)	3,637
Net cash provided by operating activities	9,438	8,653	7,833
Cash flows from investing activities [Abstract]
Net cash used in investing activities	(98,370)	(23,637)	(15,413)
Cash flows from financing activities [Abstract]
Cash dividends paid on common stock	(2,198)	(1,983)	(1,686)
Net cash provided by financing activities	77,490	3,848	11,265
Net increase (decrease) in cash and cash equivalents	(11,442)	(11,136)	3,685
Cash and cash equivalents at beginning of period	25,854	36,990	33,305
Cash and cash equivalents at end of period	14,412	25,854	36,990
Supplemental schedule of noncash transactions [Abstract]
Unrealized gain (loss) on securities available-for-sale	1,563	(1,762)	(755)
Parent Company [Member]
Cash flows from operating activities [Abstract]
Net income (loss)	(29)	3,797	3,634
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Equity in undistributed net income (loss) of subsidiaries	1,383	(1,690)	(1,109)
Stock compensation expense	17	0	0
Increase (decrease) in other assets	(34)	5	(5)
Increase (decrease) in other liabilities	10	(7)	15
Net cash provided by operating activities	1,347	2,105	2,535
Cash flows from investing activities [Abstract]
Net cash used in investing activities	0	0	0
Cash flows from financing activities [Abstract]
Proceeds from sale of stock	1,107	46	0
Cash dividends paid on common stock	(2,198)	(1,983)	(1,686)
Net cash provided by financing activities	(1,091)	(1,937)	(1,686)
Net increase (decrease) in cash and cash equivalents	256	168	849
Cash and cash equivalents at beginning of period	2,366	2,198	1,349
Cash and cash equivalents at end of period	2,622	2,366	2,198
Supplemental schedule of noncash transactions [Abstract]
Unrealized gain (loss) on securities available-for-sale	$ 33	$ 64	$ (1)