Securities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) Security	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) Security
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost	$ 149,325		$ 158,192
Gross unrealized gains	239		808
Gross unrealized losses	(3,707)		(1,879)
Fair value	145,857		157,121
Available-for-sale Securities, Realized Gains (Losses) [Abstract]
Realized gains on sales of securities	80	$ 0
Realized losses on sales of securities	0	0
Net realized gain (loss)	80	$ 0
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Less Than Twelve Months	553		112
More Than Twelve Months	3,154		1,767
Gross Unrealized Losses	3,707		1,879
Securities Available-for-Sale, Fair Value [Abstract]
Less than Twelve Months	31,500		25,170
More Than Twelve Months	78,861		79,434
Total	$ 110,361		$ 104,604
Unrealized loss position, Number of securities | Security	100		77
Obligations of U.S. Government Agencies [Member]
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost	$ 9,440		$ 9,530
Gross unrealized gains	25		27
Gross unrealized losses	(128)		(122)
Fair value	9,337		9,435
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Less Than Twelve Months	7		11
More Than Twelve Months	121		111
Gross Unrealized Losses	128		122
Securities Available-for-Sale, Fair Value [Abstract]
Less than Twelve Months	1,492		3,189
More Than Twelve Months	3,283		3,089
Total	4,775		6,278
Obligations of States and Political Subdivisions [Member]
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost	59,924		64,413
Gross unrealized gains	150		489
Gross unrealized losses	(805)		(137)
Fair value	59,269		64,765
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Less Than Twelve Months	405		32
More Than Twelve Months	400		105
Gross Unrealized Losses	805		137
Securities Available-for-Sale, Fair Value [Abstract]
Less than Twelve Months	22,103		11,141
More Than Twelve Months	10,658		10,999
Total	32,761		22,140
Mortgage-backed Securities [Member]
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost	73,699		75,906
Gross unrealized gains	0		0
Gross unrealized losses	(2,758)		(1,610)
Fair value	70,941		74,296
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Less Than Twelve Months	136		67
More Than Twelve Months	2,622		1,543
Gross Unrealized Losses	2,758		1,610
Securities Available-for-Sale, Fair Value [Abstract]
Less than Twelve Months	6,810		9,742
More Than Twelve Months	64,131		64,554
Total	70,941		74,296
Money Market Investments [Member]
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost	1,612		1,194
Gross unrealized gains	0		0
Gross unrealized losses	0		0
Fair value	1,612		1,194
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Gross Unrealized Losses	0		0
Corporate Bond and Other Securities [Member]
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost	4,650		7,049
Gross unrealized gains	64		195
Gross unrealized losses	(16)		(10)
Fair value	4,698		7,234
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Less Than Twelve Months	5		2
More Than Twelve Months	11		8
Gross Unrealized Losses	16		10
Securities Available-for-Sale, Fair Value [Abstract]
Less than Twelve Months	1,095		1,098
More Than Twelve Months	789		792
Total	$ 1,884		1,890
Other Marketable Equity Securities [Member]
Amortized cost and fair value of securities available-for-sale [Abstract]
Amortized cost			100
Gross unrealized gains			97
Gross unrealized losses			0
Fair value			197
Securities Available-for-Sale, Gross Unrealized Losses [Abstract]
Gross Unrealized Losses			$ 0