Securities (Details) $ in Thousands		3 Months Ended		9 Months Ended		12 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 Basis [Abstract]
Amortized Cost		$ 545,672		$ 545,672		$ 615,709
Unrealized Gains		5,023		5,023		2,548
Unrealized Losses		1,830		1,830		7,641
Fair Value		548,865		548,865		610,616
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		99,858		99,858		286,522
Less Than Twelve Months, Unrealized Losses		780		780		5,739
Twelve Months or More, Fair Value		75,203		75,203		68,405
Twelve Months or More, Unrealized Losses		1,050		1,050		1,902
Total, Fair Value		175,061		175,061		354,927
Total, Unrealized Losses		1,830		1,830		7,641
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value		2,173		2,173
Amortized cost		1,779		1,779
Non-credit unrealized loss		0		0
Unrealized gain		394		394
Cumulative credit related OTTI		1,594		1,594
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance at beginning of period		1,844	$ 1,844	1,844	$ 1,844	1,844
Additions to credit losses on securities for which no previous OTTI was recognized		0	0	0	0
Increases to credit losses on securities for which OTTI was previously recognized		0	0	0	0
Balance at end of period		1,844	1,844	1,844	1,844	1,844
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Maturing within one year		27,811		27,811
Maturing after one year but within five years		98,784		98,784
Maturing after five years but within ten years		82,590		82,590
Maturing after ten years		55,596		55,596
Available-for-sale securities, debt maturities, amortized cost basis		264,781		264,781
U.S. agency residential mortgage-backed		135,293		135,293
U.S. agency commercial mortgage-backed		10,767		10,767
Private label mortgage-backed		26,703		26,703
Other asset backed		108,128		108,128
Total		545,672		545,672
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Maturing within one year		27,865		27,865
Maturing after one year but within five years		99,533		99,533
Maturing after five years but within ten years		83,671		83,671
Maturing after ten years		55,622		55,622
Total available-for-sale securities fair value		266,691		266,691
U.S. agency residential mortgage-backed		136,109		136,109
U.S. agency commercial mortgage-backed		10,736		10,736
Private label mortgage-backed		26,990		26,990
Other asset backed		108,339		108,339
Total		548,865		548,865
Gain and losses realized on sale of securities available for sale [Abstract]
Proceeds	[1]			9,594	56,451
Realized gains				125	350
Realized losses				0	52
Sale of securities available for sale not yet settled				760	0
Credit related OTTI recognized in earnings		0	$ 0	0	0
Trading securities, realized gains (losses)				(63)	$ 4
Cumulative Retrospective Adjustments [Member] | ASU 2017-08 [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Adjustment in amortized cost of available for sale securities						(460)
U.S. Agency [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		26,455		26,455		28,909
Unrealized Gains		210		210		159
Unrealized Losses		39		39		80
Fair Value		26,626		26,626		28,988
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		4,819		4,819		4,179
Less Than Twelve Months, Unrealized Losses		21		21		41
Twelve Months or More, Fair Value		4,947		4,947		8,217
Twelve Months or More, Unrealized Losses		18		18		39
Total, Fair Value		9,766		9,766		12,396
Total, Unrealized Losses		$ 39		$ 39		80
Number of securities with market fair value less than amortized cost | Security		33		33
U.S. Agency Residential Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		$ 135,293		$ 135,293		156,053
Unrealized Gains		1,331		1,331		1,173
Unrealized Losses		515		515		937
Fair Value		136,109		136,109		156,289
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		24,116		24,116		62,524
Less Than Twelve Months, Unrealized Losses		215		215		732
Twelve Months or More, Fair Value		27,817		27,817		20,857
Twelve Months or More, Unrealized Losses		300		300		205
Total, Fair Value		51,933		51,933		83,381
Total, Unrealized Losses		$ 515		$ 515		937
Number of securities with market fair value less than amortized cost | Security		109		109
U.S. Agency Commercial Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		$ 10,767		$ 10,767		12,799
Unrealized Gains		84		84		28
Unrealized Losses		115		115		195
Fair Value		10,736		10,736		12,632
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		1,815		1,815		6,079
Less Than Twelve Months, Unrealized Losses		22		22		194
Twelve Months or More, Fair Value		3,933		3,933		143
Twelve Months or More, Unrealized Losses		93		93		1
Total, Fair Value		5,748		5,748		6,222
Total, Unrealized Losses		$ 115		$ 115		195
Number of securities with market fair value less than amortized cost | Security		10		10
Private Label Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		$ 26,703		$ 26,703		35,035
Unrealized Gains		518		518		216
Unrealized Losses		231		231		524
Fair Value		26,990		26,990		34,727
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		3,423		3,423		20,545
Less Than Twelve Months, Unrealized Losses		26		26		281
Twelve Months or More, Fair Value		3,163		3,163		1,413
Twelve Months or More, Unrealized Losses		205		205		243
Total, Fair Value		6,586		6,586		21,958
Total, Unrealized Losses		$ 231		$ 231		524
Number of securities with market fair value less than amortized cost | Security		11		11
Number of securities purchased prior to 2016 | Security		3		3
Number of securities with impairment in excess of ten percent | Security		2		2
Percentage of excess impairment on securities		10.00%		10.00%
Number of securities with impairment for more than 12 months | Security		3		3
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Number of private label mortgage backed securities currently with OTTI unrealized gains | Security		3		3
Number of private label mortgage backed securities complete recovery of cost basis | Security		3		3
Senior Security [Member]
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value		$ 1,076		$ 1,076
Amortized cost		937		937
Non-credit unrealized loss		0		0
Unrealized gain		139		139
Cumulative credit related OTTI		757		757
Super Senior Security [Member]
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value		1,032		1,032
Amortized cost		842		842
Non-credit unrealized loss		0		0
Unrealized gain		190		190
Cumulative credit related OTTI		457		457
Senior Support Security [Member]
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value		65		65
Amortized cost		0		0
Non-credit unrealized loss		0		0
Unrealized gain		65		65
Cumulative credit related OTTI		380		380
Other Asset Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		108,128		108,128		146,829
Unrealized Gains		319		319		271
Unrealized Losses		108		108		391
Fair Value		108,339		108,339		146,709
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		12,756		12,756		52,958
Less Than Twelve Months, Unrealized Losses		18		18		172
Twelve Months or More, Fair Value		16,298		16,298		17,763
Twelve Months or More, Unrealized Losses		90		90		219
Total, Fair Value		29,054		29,054		70,721
Total, Unrealized Losses		$ 108		$ 108		391
Number of securities with market fair value less than amortized cost | Security		51		51
Obligations of States and Political Subdivisions [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		$ 176,087		$ 176,087		175,180
Unrealized Gains		1,708		1,708		478
Unrealized Losses		619		619		4,759
Fair Value		177,176		177,176		170,899
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		42,186		42,186		113,078
Less Than Twelve Months, Unrealized Losses		447		447		4,014
Twelve Months or More, Fair Value		13,787		13,787		14,623
Twelve Months or More, Unrealized Losses		172		172		745
Total, Fair Value		55,973		55,973		127,701
Total, Unrealized Losses		$ 619		$ 619		4,759
Number of securities with market fair value less than amortized cost | Security		182		182
Corporate [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		$ 57,213		$ 57,213		56,356
Unrealized Gains		853		853		223
Unrealized Losses		66		66		399
Fair Value		58,000		58,000		56,180
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		8,654		8,654		25,546
Less Than Twelve Months, Unrealized Losses		22		22		292
Twelve Months or More, Fair Value		2,458		2,458		2,810
Twelve Months or More, Unrealized Losses		44		44		107
Total, Fair Value		11,112		11,112		28,356
Total, Unrealized Losses		$ 66		$ 66		399
Number of securities with market fair value less than amortized cost | Security		11		11
Trust Preferred [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		$ 2,928		$ 2,928		2,922
Unrealized Gains		0		0		0
Unrealized Losses		128		128		343
Fair Value		2,800		2,800		2,579
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		0		0		0
Less Than Twelve Months, Unrealized Losses		0		0		0
Twelve Months or More, Fair Value		2,800		2,800		2,579
Twelve Months or More, Unrealized Losses		128		128		343
Total, Fair Value		2,800		2,800		2,579
Total, Unrealized Losses		$ 128		$ 128		343
Number of securities with market fair value less than amortized cost | Security		3		3
Number of issues rated as investment grade | Security		1		1
Number of securities rated as below investment grade | Security		1		1
Number of major credit rating agencies rating securities with fair value less than amortized cost | Security		2		2
Number of securities non-rated | Security		1		1
Non-rated trust preferred securities, amortized cost		$ 1,000		$ 1,000
Non-rated trust preferred securities, fair value		900		900
Rated Issues [Member]
Trust preferred securities [Abstract]
Fair Value		1,880		1,880		1,800
Net Unrealized Loss				(48)		(123)
Unrated Issues [Member]
Trust preferred securities [Abstract]
Fair Value		920		920		779
Net Unrealized Loss				(80)		(220)
Foreign Government [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost		2,098		2,098		1,626
Unrealized Gains		0		0		0
Unrealized Losses		9		9		13
Fair Value		2,089		2,089		1,613
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value		2,089		2,089		1,613
Less Than Twelve Months, Unrealized Losses		9		9		13
Twelve Months or More, Fair Value		0		0		0
Twelve Months or More, Unrealized Losses		0		0		0
Total, Fair Value		2,089		2,089		1,613
Total, Unrealized Losses		$ 9		$ 9		$ 13
Number of securities with market fair value less than amortized cost | Security		2		2

[1] 2017 includes $0.760 million for trades that did not settle until after September 30, 2017.