Investments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) Security	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) Security	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost	$ 261,377		$ 261,377		$ 312,039
Gross unrealized gains	2,701		2,701		3,087
Gross unrealized losses	(490)		(490)		(1,109)
Fair value	$ 263,588		$ 263,588		314,017
Number of securities owned with fair value less than cost | Security	70		70
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than twelve months, Fair value	$ 87,877		$ 87,877		106,062
Twelve months or greater, Fair value	19,296		19,296		1,520
Total, Fair value	107,173		107,173		107,582
Less than twelve months, Gross unrealized losses	(306)		(306)		(1,071)
Twelve months or greater, Gross unrealized losses	(184)		(184)		(38)
Total, Gross Unrealized Losses	(490)		(490)		(1,109)
Proceeds from sale of securities available-for-sale	4,986	$ 0	30,393	$ 12,077
Realized investment gains (losses) [Abstract]
Gross gains	9	0	211	155
Gross losses	0	0	(7)	0
Net gains	9	$ 0	204	$ 155
Investment securities pledged as collateral	243,900		243,900		206,300
Available-for-Sale Debt Securities, Amortized Cost [Abstract]
Due in one year or less	52,243		52,243
Due after one year through five years	113,014		113,014
Due after five years through ten years	35,712		35,712
Due after ten years	59,416		59,416
Total	260,385		260,385
Available-for-Sale Debt Securities, Fair Value [Abstract]
Due in one year or less	52,375		52,375
Due after one year through five years	113,722		113,722
Due after five years through ten years	35,950		35,950
Due after ten years	59,605		59,605
Total	261,652		261,652
U.S. Agency Securities [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost	132,555		132,555		170,276
Gross unrealized gains	191		191		407
Gross unrealized losses	(195)		(195)		(269)
Fair value	132,551		132,551		170,414
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than twelve months, Fair value	55,048		55,048		50,947
Twelve months or greater, Fair value	7,922		7,922		0
Total, Fair value	62,970		62,970		50,947
Less than twelve months, Gross unrealized losses	(119)		(119)		(269)
Twelve months or greater, Gross unrealized losses	(76)		(76)		0
Total, Gross Unrealized Losses	(195)		(195)		(269)
U.S. Treasury Securities [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost					2,999
Gross unrealized gains					1
Gross unrealized losses					0
Fair value					3,000
Obligations of State and Political Subdivisions [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost	80,439		80,439		95,956
Gross unrealized gains	1,382		1,382		1,463
Gross unrealized losses	(98)		(98)		(493)
Fair value	81,723		81,723		96,926
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than twelve months, Fair value	6,146		6,146		28,398
Twelve months or greater, Fair value	8,564		8,564		767
Total, Fair value	14,710		14,710		29,165
Less than twelve months, Gross unrealized losses	(21)		(21)		(472)
Twelve months or greater, Gross unrealized losses	(77)		(77)		(21)
Total, Gross Unrealized Losses	(98)		(98)		(493)
Corporate Obligations [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost	3,000		3,000		3,000
Gross unrealized gains	101		101		50
Gross unrealized losses	0		0		0
Fair value	3,101		3,101		3,050
Mortgage-backed Securities in Government Sponsored Entities [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost	44,391		44,391		37,987
Gross unrealized gains	83		83		88
Gross unrealized losses	(197)		(197)		(347)
Fair value	44,277		44,277		37,728
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than twelve months, Fair value	26,683		26,683		26,717
Twelve months or greater, Fair value	2,810		2,810		753
Total, Fair value	29,493		29,493		27,470
Less than twelve months, Gross unrealized losses	(166)		(166)		(330)
Twelve months or greater, Gross unrealized losses	(31)		(31)		(17)
Total, Gross Unrealized Losses	(197)		(197)		(347)
Equity Securities in Financial Institutions [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized cost	992		992		1,821
Gross unrealized gains	944		944		1,078
Gross unrealized losses	0		0		0
Fair value	$ 1,936		$ 1,936		$ 2,899