Securities (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($) Security	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Security	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	$ 456,209		$ 456,209		$ 523,520
Unrealized Gains	1,847		1,847		3,197
Unrealized Losses	7,463		7,463		3,792
Fair Value	450,593		450,593		522,925
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	197,432		197,432		153,090
Less Than Twelve Months, Unrealized Losses	3,717		3,717		1,400
Twelve Months or More, Fair Value	104,861		104,861		108,033
Twelve Months or More, Unrealized Losses	3,746		3,746		2,392
Total, Fair Value	302,293		302,293		261,123
Total, Unrealized Losses	7,463		7,463		3,792
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value	1,806		1,806
Amortized cost	1,441		1,441
Non-credit unrealized loss	0		0
Unrealized gain	365		365
Cumulative credit related OTTI	1,594		1,594
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance at beginning of period	1,594	$ 1,594	1,594	$ 1,594	1,594
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	1,594	1,594	1,594	1,594	1,594
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Maturing within one year	16,943		16,943
Maturing after one year but within five years	79,682		79,682
Maturing after five years but within ten years	61,039		61,039
Maturing after ten years	49,684		49,684
Available-for-sale securities, debt maturities, amortized cost basis	207,348		207,348
U.S. agency residential mortgage-backed	131,317		131,317
U.S. agency commercial mortgage-backed	9,659		9,659
Private label mortgage-backed	30,593		30,593
Other asset backed	77,292		77,292
Amortized Cost	456,209		456,209		523,520
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Maturing within one year	16,925		16,925
Maturing after one year but within five years	78,851		78,851
Maturing after five years but within ten years	59,771		59,771
Maturing after ten years	48,098		48,098
Total available-for-sale securities fair value	203,645		203,645
U.S. agency residential mortgage-backed	130,001		130,001
U.S. agency commercial mortgage-backed	9,384		9,384
Private label mortgage-backed	30,283		30,283
Other asset backed	77,280		77,280
Total	450,593		450,593		522,925
Gain and losses realized on sale of securities available for sale [Abstract]
Proceeds			31,445	7,830
Realized gains			81	117
Realized losses			126	0
Credit related OTTI recognized in earnings	0	$ 0	0	0
Trading securities, realized losses			(119)	$ (124)
U.S. Treasury [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost					898
Unrealized Gains					0
Unrealized Losses					0
Fair Value					898
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost					898
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total					898
U.S. Agency [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	23,094		23,094		25,667
Unrealized Gains	3		3		82
Unrealized Losses	285		285		67
Fair Value	22,812		22,812		25,682
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	13,530		13,530		5,466
Less Than Twelve Months, Unrealized Losses	211		211		26
Twelve Months or More, Fair Value	7,843		7,843		5,735
Twelve Months or More, Unrealized Losses	74		74		41
Total, Fair Value	21,373		21,373		11,201
Total, Unrealized Losses	$ 285		$ 285		67
Number of securities with market fair value less than amortized cost | Security	46		46
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 23,094		$ 23,094		25,667
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	22,812		22,812		25,682
U.S. Agency Residential Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	131,317		131,317		137,785
Unrealized Gains	874		874		1,116
Unrealized Losses	2,190		2,190		983
Fair Value	130,001		130,001		137,918
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	39,328		39,328		22,198
Less Than Twelve Months, Unrealized Losses	988		988		229
Twelve Months or More, Fair Value	31,119		31,119		40,698
Twelve Months or More, Unrealized Losses	1,202		1,202		754
Total, Fair Value	70,447		70,447		62,896
Total, Unrealized Losses	$ 2,190		$ 2,190		983
Number of securities with market fair value less than amortized cost | Security	135		135
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 131,317		$ 131,317		137,785
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	130,001		130,001		137,918
U.S. Agency Commercial Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	9,659		9,659		9,894
Unrealized Gains	1		1		36
Unrealized Losses	276		276		170
Fair Value	9,384		9,384		9,760
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	4,294		4,294		2,181
Less Than Twelve Months, Unrealized Losses	57		57		34
Twelve Months or More, Fair Value	4,996		4,996		3,994
Twelve Months or More, Unrealized Losses	219		219		136
Total, Fair Value	9,290		9,290		6,175
Total, Unrealized Losses	$ 276		$ 276		170
Number of securities with market fair value less than amortized cost | Security	18		18
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 9,659		$ 9,659		9,894
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	9,384		9,384		9,760
Private Label Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	30,593		30,593		29,011
Unrealized Gains	392		392		428
Unrealized Losses	702		702		330
Fair Value	30,283		30,283		29,109
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	16,797		16,797		11,390
Less Than Twelve Months, Unrealized Losses	423		423		92
Twelve Months or More, Fair Value	4,107		4,107		4,396
Twelve Months or More, Unrealized Losses	279		279		238
Total, Fair Value	20,904		20,904		15,786
Total, Unrealized Losses	$ 702		$ 702		330
Number of securities with market fair value less than amortized cost | Security	29		29
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Number of private label mortgage backed securities complete recovery of cost basis | Security	2		2
Number of private label mortgage backed securities currently with OTTI unrealized gains | Security	3		3
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 30,593		$ 30,593		29,011
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	30,283		30,283		29,109
Senior Security [Member]
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value	887		887
Amortized cost	737		737
Non-credit unrealized loss	0		0
Unrealized gain	150		150
Cumulative credit related OTTI	757		757
Super Senior Security [Member]
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value	873		873
Amortized cost	704		704
Non-credit unrealized loss	0		0
Unrealized gain	169		169
Cumulative credit related OTTI	457		457
Senior Support Security [Member]
Private Label Mortgage Backed Securities Below Investment Grade [Abstract]
Fair value	46		46
Amortized cost	0		0
Non-credit unrealized loss	0		0
Unrealized gain	46		46
Cumulative credit related OTTI	380		380
Other Asset Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	77,292		77,292		93,811
Unrealized Gains	170		170		202
Unrealized Losses	182		182		115
Fair Value	77,280		77,280		93,898
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	27,318		27,318		20,352
Less Than Twelve Months, Unrealized Losses	109		109		40
Twelve Months or More, Fair Value	11,003		11,003		16,648
Twelve Months or More, Unrealized Losses	73		73		75
Total, Fair Value	38,321		38,321		37,000
Total, Unrealized Losses	$ 182		$ 182		115
Number of securities with market fair value less than amortized cost | Security	75		75
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 77,292		$ 77,292		93,811
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	77,280		77,280		93,898
Obligations of States and Political Subdivisions [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	146,941		146,941		174,073
Unrealized Gains	343		343		755
Unrealized Losses	3,205		3,205		1,883
Fair Value	144,079		144,079		172,945
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	75,486		75,486		76,574
Less Than Twelve Months, Unrealized Losses	1,534		1,534		936
Twelve Months or More, Fair Value	38,012		38,012		28,246
Twelve Months or More, Unrealized Losses	1,671		1,671		947
Total, Fair Value	113,498		113,498		104,820
Total, Unrealized Losses	$ 3,205		$ 3,205		1,883
Number of securities with market fair value less than amortized cost | Security	342		342
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 146,941		$ 146,941		174,073
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	144,079		144,079		172,945
Corporate [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	33,285		33,285		47,365
Unrealized Gains	64		64		578
Unrealized Losses	514		514		90
Fair Value	32,835		32,835		47,853
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	20,679		20,679		14,440
Less Than Twelve Months, Unrealized Losses	395		395		33
Twelve Months or More, Fair Value	3,862		3,862		3,943
Twelve Months or More, Unrealized Losses	119		119		57
Total, Fair Value	24,541		24,541		18,383
Total, Unrealized Losses	$ 514		$ 514		90
Number of securities with market fair value less than amortized cost | Security	30		30
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 33,285		$ 33,285		47,365
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	32,835		32,835		47,853
Trust Preferred [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	1,959		1,959		2,929
Unrealized Gains	0		0		0
Unrealized Losses	61		61		127
Fair Value	1,898		1,898		2,802
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	1,898		1,898		2,802
Twelve Months or More, Unrealized Losses	61		61		127
Total, Fair Value	1,898		1,898		2,802
Total, Unrealized Losses	$ 61		$ 61		127
Number of securities with market fair value less than amortized cost | Security	2		2
Number of issues rated as investment grade | Security	1		1
Number of major credit rating agencies rating securities with fair value less than amortized cost | Security	1		1
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	970		970
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	1,959		1,959		2,929
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	1,898		1,898		2,802
Rated Issues [Member]
Trust preferred securities [Abstract]
Fair Value	935		935		1,860
Net Unrealized Loss			(27)		(69)
Unrated Issues [Member]
Trust preferred securities [Abstract]
Fair Value	963		963		942
Net Unrealized Loss			(34)		(58)
Foreign Government [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost	2,069		2,069		2,087
Unrealized Gains	0		0		0
Unrealized Losses	48		48		27
Fair Value	2,021		2,021		2,060
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	0		0		489
Less Than Twelve Months, Unrealized Losses	0		0		10
Twelve Months or More, Fair Value	2,021		2,021		1,571
Twelve Months or More, Unrealized Losses	48		48		17
Total, Fair Value	2,021		2,021		2,060
Total, Unrealized Losses	$ 48		$ 48		27
Number of securities with market fair value less than amortized cost | Security	2		2
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Amortized Cost	$ 2,069		$ 2,069		2,087
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Total	$ 2,021		$ 2,021		$ 2,060