Loans, Loan Ratings by Loan Class, Commercial, Mortgage and Installment Segments (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
		Mar. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Loan ratings/credit scores by loan class [Abstract]
Commercial			$ 1,106,987		$ 1,106,987		$ 853,260
Accrued interest included in total			8,117		8,117		6,501
Other Real Estate and Foreclosed Assets [Abstract]
Foreclosed residential real estate properties			1,700		1,700		1,600
Retail mortgage loans in process of foreclosure			300		300		800
Sale of Mortgage Loans [Abstract]
Proceeds from sale of mortgage loan					16,460	$ 0
Net gains on mortgage loans			(3,255)	$ (3,344)	(5,826)	$ (5,915)
Loans held for sale			49,704		49,704		38,592
Single-family Residential Loans [Member]
Sale of Mortgage Loans [Abstract]
Proceeds from sale of mortgage loan		$ 16,500
Net gains on mortgage loans		$ 50
Weighted average interest rate		3.59%
Loans held for sale			13,200		13,200
Commercial [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			1,110,107		1,110,107		855,560
Accrued interest included in total			3,120		3,120		2,300
Commercial [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			1,061,339		1,061,339		822,561
Accrued interest included in total			2,899		2,899		2,198
Commercial [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			35,897		35,897		29,704
Accrued interest included in total			144		144		94
Commercial [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			9,982		9,982		2,649
Accrued interest included in total			77		77		8
Commercial [Member] | Non-Accrual 10-11 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			2,889		2,889		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			365,766		365,766		290,496
Commercial [Member] | Income Producing - Real Estate [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			362,860		362,860		288,869
Commercial [Member] | Income Producing - Real Estate [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			2,452		2,452		1,293
Commercial [Member] | Income Producing - Real Estate [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			454		454		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			61,755		61,755		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			52,832		52,832		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			6,509		6,509		60
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			12		12		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			682,586		682,586		494,873
Commercial [Member] | Commercial and Industrial [Member] | Non-Watch 1-6 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			645,647		645,647		463,570
Commercial [Member] | Commercial and Industrial [Member] | Watch 7-8 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			26,936		26,936		28,351
Commercial [Member] | Commercial and Industrial [Member] | Substandard Accrual 9 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			9,516		9,516		2,345
Commercial [Member] | Commercial and Industrial [Member] | Non-Accrual 10-11 [Member]
Loan ratings/credit scores by loan class [Abstract]
Commercial			487		487		607
Mortgage [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]		134,181		134,181		104,159
750-799	[1]		406,036		406,036		360,260
700-749	[1]		241,854		241,854		198,667
650-699	[1]		116,004		116,004		106,479
600-649	[1]		36,608		36,608		31,813
550-599	[1]		17,032		17,032		19,482
500-549	[1]		10,165		10,165		12,110
Under 500	[1]		2,093		2,093		3,463
Unknown	[1]		28,638		28,638		16,375
Total	[1]		992,611		992,611		852,808
Accrued interest included in total	[1]		3,989		3,989		3,278
Mortgage [Member] | 1-4 Family [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]		105,921		105,921		78,523
750-799	[1]		327,242		327,242		283,558
700-749	[1]		192,813		192,813		154,239
650-699	[1]		95,852		95,852		84,121
600-649	[1]		29,042		29,042		25,087
550-599	[1]		13,706		13,706		15,136
500-549	[1]		7,788		7,788		9,548
Under 500	[1]		1,729		1,729		2,549
Unknown	[1]		9,953		9,953		14,472
Total	[1]		784,046		784,046		667,233
Accrued interest included in total	[1]		2,889		2,889		2,456
Mortgage [Member] | Resort Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]		12,496		12,496		11,625
750-799	[1]		32,448		32,448		36,015
700-749	[1]		21,108		21,108		22,099
650-699	[1]		9,246		9,246		12,145
600-649	[1]		4,490		4,490		3,025
550-599	[1]		1,232		1,232		2,710
500-549	[1]		949		949		1,009
Under 500	[1]		85		85		269
Unknown	[1]		2,262		2,262		1,659
Total	[1]		84,316		84,316		90,556
Accrued interest included in total	[1]		364		364		371
Mortgage [Member] | Home Equity - 1st Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]		7,184		7,184		6,169
750-799	[1]		17,542		17,542		16,561
700-749	[1]		8,625		8,625		7,317
650-699	[1]		3,055		3,055		2,793
600-649	[1]		530		530		1,189
550-599	[1]		778		778		518
500-549	[1]		230		230		397
Under 500	[1]		89		89		260
Unknown	[1]		7,251		7,251		157
Total	[1]		45,284		45,284		35,361
Accrued interest included in total	[1]		262		262		157
Mortgage [Member] | Home Equity - 2nd Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[1]		8,580		8,580		7,842
750-799	[1]		28,804		28,804		24,126
700-749	[1]		19,308		19,308		15,012
650-699	[1]		7,851		7,851		7,420
600-649	[1]		2,546		2,546		2,512
550-599	[1]		1,316		1,316		1,118
500-549	[1]		1,198		1,198		1,156
Under 500	[1]		190		190		385
Unknown	[1]		9,172		9,172		87
Total	[1]		78,965		78,965		59,658
Accrued interest included in total	[1]		474		474		294
Installment [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]		50,034		50,034		40,985
750-799	[2]		189,420		189,420		158,147
700-749	[2]		82,238		82,238		70,941
650-699	[2]		25,549		25,549		26,583
600-649	[2]		7,453		7,453		7,840
550-599	[2]		3,650		3,650		3,794
500-549	[2]		1,350		1,350		1,641
Under 500	[2]		442		442		377
Unknown	[2]		12,580		12,580		6,642
Total	[2]		372,716		372,716		316,950
Accrued interest included in total	[2]		1,008		1,008		923
Installment [Member] | Home Equity - 1st Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]		607		607		815
750-799	[2]		2,005		2,005		1,912
700-749	[2]		1,286		1,286		1,825
650-699	[2]		1,597		1,597		1,840
600-649	[2]		1,181		1,181		1,567
550-599	[2]		945		945		950
500-549	[2]		225		225		499
Under 500	[2]		58		58		32
Unknown	[2]		1,218		1,218		15
Total	[2]		9,122		9,122		9,455
Accrued interest included in total	[2]		37		37		39
Installment [Member] | Home Equity - 2nd Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]		330		330		825
750-799	[2]		1,718		1,718		1,952
700-749	[2]		2,059		2,059		2,142
650-699	[2]		1,743		1,743		2,036
600-649	[2]		1,103		1,103		1,065
550-599	[2]		890		890		1,028
500-549	[2]		137		137		303
Under 500	[2]		143		143		88
Unknown	[2]		280		280		32
Total	[2]		8,403		8,403		9,471
Accrued interest included in total	[2]		36		36		43
Installment [Member] | Boat Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]		23,002		23,002		15,531
750-799	[2]		88,646		88,646		73,251
700-749	[2]		34,972		34,972		28,922
650-699	[2]		8,387		8,387		9,179
600-649	[2]		2,015		2,015		2,052
550-599	[2]		422		422		640
500-549	[2]		448		448		281
Under 500	[2]		45		45		57
Unknown	[2]		1,349		1,349		59
Total	[2]		159,286		159,286		129,972
Accrued interest included in total	[2]		394		394		346
Installment [Member] | Recreational Vehicle Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]		20,133		20,133		16,754
750-799	[2]		66,538		66,538		52,610
700-749	[2]		21,023		21,023		17,993
650-699	[2]		4,126		4,126		4,270
600-649	[2]		835		835		754
550-599	[2]		368		368		305
500-549	[2]		79		79		83
Under 500	[2]		22		22		6
Unknown	[2]		74		74		35
Total	[2]		113,198		113,198		92,810
Accrued interest included in total	[2]		288		288		254
Installment [Member] | Other [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above	[2]		5,962		5,962		7,060
750-799	[2]		30,513		30,513		28,422
700-749	[2]		22,898		22,898		20,059
650-699	[2]		9,696		9,696		9,258
600-649	[2]		2,319		2,319		2,402
550-599	[2]		1,025		1,025		871
500-549	[2]		461		461		475
Under 500	[2]		174		174		194
Unknown	[2]		9,659		9,659		6,501
Total	[2]		82,707		82,707		75,242
Accrued interest included in total	[2]		$ 253		$ 253		$ 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.