Investments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) Security	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Security	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized Cost	$ 343,532		$ 343,532		$ 356,399
Gross Unrealized Gains	5,701		5,701		4,139
Gross Unrealized Losses	(79)		(79)		(801)
Fair Value	$ 349,154		$ 349,154		359,737
Number of securities owned with fair value less than cost | Security	24		24
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value	$ 19,810		$ 19,810		156,454
Twelve Months or Greater, Fair Value	1,855		1,855		5,279
Total, Fair Value	21,665		21,665		161,733
Less than Twelve Months, Gross Unrealized Losses	(64)		(64)		(748)
Twelve Months or Greater, Gross Unrealized Losses	(15)		(15)		(53)
Total, Gross Unrealized Losses	(79)		$ (79)		(801)
Duration securities impaired, minimum			1 year
Proceeds from sale of securities available-for-sale	0	$ 5,187	$ 12,077	$ 18,393
Realized investment gains (losses) [Abstract]
Gross gains	0	129	155	441
Gross losses	0	0	0	(11)
Net gains	0	$ 129	155	$ 430
Investment securities pledged as collateral	224,900		224,900		203,800
Available-for-Sale Debt Securities, Amortized Cost [Abstract]
Due in one year or less	49,510		49,510
Due after one year through five years	173,075		173,075
Due after five years through ten years	41,247		41,247
Due after ten years	77,698		77,698
Total	341,530		341,530
Available-for-Sale Debt Securities, Fair Value [Abstract]
Due in one year or less	49,724		49,724
Due after one year through five years	175,690		175,690
Due after five years through ten years	42,129		42,129
Due after ten years	78,893		78,893
Total	346,436		346,436
U.S. Agency Securities [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized Cost	188,936		188,936		199,749
Gross Unrealized Gains	1,839		1,839		369
Gross Unrealized Losses	(9)		(9)		(527)
Fair Value	190,766		190,766		199,591
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value	6,998		6,998		123,591
Twelve Months or Greater, Fair Value	0		0		0
Total, Fair Value	6,998		6,998		123,591
Less than Twelve Months, Gross Unrealized Losses	(9)		(9)		(527)
Twelve Months or Greater, Gross Unrealized Losses	0		0		0
Total, Gross Unrealized Losses	(9)		(9)		(527)
U.S. Treasury Securities [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized Cost	5,013		5,013		10,103
Gross Unrealized Gains	7		7		0
Gross Unrealized Losses	0		0		(21)
Fair Value	5,020		5,020		10,082
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value					10,082
Twelve Months or Greater, Fair Value					0
Total, Fair Value					10,082
Less than Twelve Months, Gross Unrealized Losses					(21)
Twelve Months or Greater, Gross Unrealized Losses					0
Total, Gross Unrealized Losses					(21)
Obligations of State and Political Subdivisions [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized Cost	99,557		99,557		99,856
Gross Unrealized Gains	2,702		2,702		3,080
Gross Unrealized Losses	(37)		(37)		(73)
Fair Value	102,222		102,222		102,863
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value	9,244		9,244		7,023
Twelve Months or Greater, Fair Value	0		0		2,914
Total, Fair Value	9,244		9,244		9,937
Less than Twelve Months, Gross Unrealized Losses	(37)		(37)		(57)
Twelve Months or Greater, Gross Unrealized Losses	0		0		(16)
Total, Gross Unrealized Losses	(37)		(37)		(73)
Corporate Obligations [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized Cost	14,359		14,359		14,583
Gross Unrealized Gains	17		17		68
Gross Unrealized Losses	0		0		(86)
Fair Value	14,376		14,376		14,565
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value					5,822
Twelve Months or Greater, Fair Value					2,138
Total, Fair Value					7,960
Less than Twelve Months, Gross Unrealized Losses					(61)
Twelve Months or Greater, Gross Unrealized Losses					(25)
Total, Gross Unrealized Losses					(86)
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	33,665		33,665		30,107
Gross Unrealized Gains	420		420		186
Gross Unrealized Losses	(33)		(33)		(89)
Fair Value	34,052		34,052		30,204
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value	3,568		3,568		9,830
Twelve Months or Greater, Fair Value	1,855		1,855		227
Total, Fair Value	5,423		5,423		10,057
Less than Twelve Months, Gross Unrealized Losses	(18)		(18)		(77)
Twelve Months or Greater, Gross Unrealized Losses	(15)		(15)		(12)
Total, Gross Unrealized Losses	(33)		(33)		(89)
Equity Securities in Financial Institutions [Member]
Available for Sale Securities Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value [Abstract]
Amortized Cost	2,002		2,002		2,001
Gross Unrealized Gains	716		716		436
Gross Unrealized Losses	0		0		(5)
Fair Value	$ 2,718		$ 2,718		2,432
Available-For-Sale Securities, Fair Value and Gross Unrealized Losses [Abstract]
Less than Twelve Months, Fair Value					106
Twelve Months or Greater, Fair Value					0
Total, Fair Value					106
Less than Twelve Months, Gross Unrealized Losses					(5)
Twelve Months or Greater, Gross Unrealized Losses					0
Total, Gross Unrealized Losses					$ (5)