Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Schedule of Cash and Cash Equivalents:
Cash and due from banks	$ 28,594	$ 20,268	$ 19,352
Interest-bearing deposits in other banks	23,883	32,939	75,985
Cash and cash equivalents	52,477	53,207	95,337	$ 67,303
Cash paid for:
Interest on deposits and borrowed funds	7,240	6,348	5,836
Income taxes	7,653	6,477	3,090
Noncash investing and financing activities:
Transfer of loans to other real estate owned	1,233	295	2,101
Unrealized loss on securities available for sale	(777)	(6,572)	(2,652)
Change in unfunded pension liability	(234)	166	538
Assets assumed:
Investment securities	0	0	18,507
Restricted stock	0	0	587
Loans	0	0	115,960
Premises and equipment	0	0	956
Deferred income taxes	0	0	2,794
Core deposit intangible	0	0	1,839
Other real estate owned, net	0	0	168
Bank owned life insurance	0	0	1,955
Other assets	0	0	1,049
Liabilities assumed:
Demand, MMDA, and savings deposits	0	0	82,451
Time deposits	0	0	54,872
Other liabilities	0	0	3,076
Issuance of common stock	$ 0	$ 0	$ 20,483