Loans, Loan Ratings by Loan Class, Commercial, Mortgage and Installment Segments (Details) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended		9 Months Ended
		Jul. 31, 2018	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Loan ratings/credit scores by loan class [Abstract]
Commercial				$ 1,112,101		$ 1,112,101		$ 853,260
Accrued interest included in total				8,375		8,375		6,501
Other Real Estate and Foreclosed Assets [Abstract]
Foreclosed residential real estate properties				1,300		1,300		1,600
Retail mortgage loans in process of foreclosure				400		400		800
Sale of Mortgage Loans [Abstract]
Proceeds from sale of mortgage loan						27,577	$ 0
Net gains on mortgage loans				(2,745)	$ (2,971)	(8,571)	$ (8,886)
Single-family Residential Loans [Member]
Sale of Mortgage Loans [Abstract]
Proceeds from sale of mortgage loan		$ 11,100	$ 16,500
Net gains on mortgage loans		$ (10)	$ 50
Weighted average interest rate		4.07%	3.59%
Commercial [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				1,115,227		1,115,227		855,560
Accrued interest included in total				3,126		3,126		2,300
Commercial [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				1,064,854		1,064,854		822,561
Accrued interest included in total				2,869		2,869		2,198
Commercial [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				36,857		36,857		29,704
Accrued interest included in total				146		146		94
Commercial [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				10,734		10,734		2,649
Accrued interest included in total				111		111		8
Commercial [Member] | Non-Accrual 10-11 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				2,782		2,782		646
Accrued interest included in total				0		0		0
Commercial [Member] | Income Producing - Real Estate [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				378,233		378,233		290,496
Commercial [Member] | Income Producing - Real Estate [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				374,965		374,965		288,869
Commercial [Member] | Income Producing - Real Estate [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				3,060		3,060		1,293
Commercial [Member] | Income Producing - Real Estate [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				208		208		304
Commercial [Member] | Income Producing - Real Estate [Member] | Non-Accrual 10-11 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				0		0		30
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				64,162		64,162		70,191
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				55,126		55,126		70,122
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				6,623		6,623		60
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				11		11		0
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member] | Non-Accrual 10-11 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				2,402		2,402		9
Commercial [Member] | Commercial and Industrial [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				672,832		672,832		494,873
Commercial [Member] | Commercial and Industrial [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				634,763		634,763		463,570
Commercial [Member] | Commercial and Industrial [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				27,174		27,174		28,351
Commercial [Member] | Commercial and Industrial [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				10,515		10,515		2,345
Commercial [Member] | Commercial and Industrial [Member] | Non-Accrual 10-11 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial				380		380		607
Mortgage [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]			143,013		143,013		104,159
750-799	[1]			436,180		436,180		360,260
700-749	[1]			263,937		263,937		198,667
650-699	[1]			126,427		126,427		106,479
600-649	[1]			38,173		38,173		31,813
550-599	[1]			16,475		16,475		19,482
500-549	[1]			9,896		9,896		12,110
Under 500	[1]			2,062		2,062		3,463
Unknown	[1]			24,485		24,485		16,375
Total	[1]			1,060,648		1,060,648		852,808
Accrued interest included in total	[1]			4,166		4,166		3,278
Mortgage [Member] | 1-4 Family [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]			110,400		110,400		78,523
750-799	[1]			358,072		358,072		283,558
700-749	[1]			211,575		211,575		154,239
650-699	[1]			104,395		104,395		84,121
600-649	[1]			30,578		30,578		25,087
550-599	[1]			13,491		13,491		15,136
500-549	[1]			7,641		7,641		9,548
Under 500	[1]			1,702		1,702		2,549
Unknown	[1]			13,907		13,907		14,472
Total	[1]			851,761		851,761		667,233
Accrued interest included in total	[1]			3,161		3,161		2,456
Mortgage [Member] | Resort Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]			12,423		12,423		11,625
750-799	[1]			32,498		32,498		36,015
700-749	[1]			21,239		21,239		22,099
650-699	[1]			9,271		9,271		12,145
600-649	[1]			4,142		4,142		3,025
550-599	[1]			1,220		1,220		2,710
500-549	[1]			822		822		1,009
Under 500	[1]			84		84		269
Unknown	[1]			3,108		3,108		1,659
Total	[1]			84,807		84,807		90,556
Accrued interest included in total	[1]			360		360		371
Mortgage [Member] | Home Equity - 1st Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]			7,872		7,872		6,169
750-799	[1]			15,037		15,037		16,561
700-749	[1]			9,562		9,562		7,317
650-699	[1]			3,222		3,222		2,793
600-649	[1]			569		569		1,189
550-599	[1]			503		503		518
500-549	[1]			228		228		397
Under 500	[1]			86		86		260
Unknown	[1]			3,653		3,653		157
Total	[1]			40,732		40,732		35,361
Accrued interest included in total	[1]			206		206		157
Mortgage [Member] | Home Equity - 2nd Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]			12,318		12,318		7,842
750-799	[1]			30,573		30,573		24,126
700-749	[1]			21,561		21,561		15,012
650-699	[1]			9,539		9,539		7,420
600-649	[1]			2,884		2,884		2,512
550-599	[1]			1,261		1,261		1,118
500-549	[1]			1,205		1,205		1,156
Under 500	[1]			190		190		385
Unknown	[1]			3,817		3,817		87
Total	[1]			83,348		83,348		59,658
Accrued interest included in total	[1]			439		439		294
Installment [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]			54,990		54,990		40,985
750-799	[2]			203,474		203,474		158,147
700-749	[2]			86,933		86,933		70,941
650-699	[2]			26,090		26,090		26,583
600-649	[2]			7,585		7,585		7,840
550-599	[2]			3,620		3,620		3,794
500-549	[2]			1,286		1,286		1,641
Under 500	[2]			475		475		377
Unknown	[2]			10,625		10,625		6,642
Total	[2]			395,078		395,078		316,950
Accrued interest included in total	[2]			1,083		1,083		923
Installment [Member] | Home Equity - 1st Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]			651		651		815
750-799	[2]			1,899		1,899		1,912
700-749	[2]			1,471		1,471		1,825
650-699	[2]			1,608		1,608		1,840
600-649	[2]			1,174		1,174		1,567
550-599	[2]			1,065		1,065		950
500-549	[2]			305		305		499
Under 500	[2]			87		87		32
Unknown	[2]			32		32		15
Total	[2]			8,292		8,292		9,455
Accrued interest included in total	[2]			33		33		39
Installment [Member] | Home Equity - 2nd Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]			264		264		825
750-799	[2]			1,519		1,519		1,952
700-749	[2]			1,806		1,806		2,142
650-699	[2]			1,627		1,627		2,036
600-649	[2]			1,065		1,065		1,065
550-599	[2]			850		850		1,028
500-549	[2]			132		132		303
Under 500	[2]			172		172		88
Unknown	[2]			145		145		32
Total	[2]			7,580		7,580		9,471
Accrued interest included in total	[2]			27		27		43
Installment [Member] | Boat Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]			25,231		25,231		15,531
750-799	[2]			95,664		95,664		73,251
700-749	[2]			36,743		36,743		28,922
650-699	[2]			8,760		8,760		9,179
600-649	[2]			2,064		2,064		2,052
550-599	[2]			410		410		640
500-549	[2]			340		340		281
Under 500	[2]			43		43		57
Unknown	[2]			903		903		59
Total	[2]			170,158		170,158		129,972
Accrued interest included in total	[2]			431		431		346
Installment [Member] | Recreational Vehicle Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]			22,621		22,621		16,754
750-799	[2]			72,298		72,298		52,610
700-749	[2]			22,996		22,996		17,993
650-699	[2]			4,093		4,093		4,270
600-649	[2]			778		778		754
550-599	[2]			334		334		305
500-549	[2]			76		76		83
Under 500	[2]			21		21		6
Unknown	[2]			66		66		35
Total	[2]			123,283		123,283		92,810
Accrued interest included in total	[2]			319		319		254
Installment [Member] | Other [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]			6,223		6,223		7,060
750-799	[2]			32,094		32,094		28,422
700-749	[2]			23,917		23,917		20,059
650-699	[2]			10,002		10,002		9,258
600-649	[2]			2,504		2,504		2,402
550-599	[2]			961		961		871
500-549	[2]			433		433		475
Under 500	[2]			152		152		194
Unknown	[2]			9,479		9,479		6,501
Total	[2]			85,765		85,765		75,242
Accrued interest included in total	[2]			$ 273		$ 273		$ 241

[1] Other than for the TCSB Bancorp, Inc. ("TCSB") acquired loans, credit scores have been updated within the last twelve months.

[2] Other than for the TCSB acquired loans, credit scores have been updated within the last twelve months.