Loans, Credit Scores by Loan Class, Mortgage and Installment Segments (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Loan ratings/credit scores by loan class [Abstract]
Accrued interest included in total	[1]			$ 8,899
Other Real Estate and Foreclosed Assets [Abstract]
Foreclosed residential real estate properties		$ 300		700
Retail mortgage loans in process of foreclosure		300		300
Sale of Mortgage Loans [Abstract]
Proceeds from sale of loans		0	$ 2,395
Gain on sale of loans		$ 12,828	8,840
Residential Fixed Rate Mortgage Loans [Member] | Freddie Mac [Member]
Sale of Mortgage Loans [Abstract]
Proceeds from sale of loans			26,300
Gain on sale of loans			720
Mortgage [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				148,768
750-799				445,611
700-749				241,589
650-699				115,484
600-649				38,341
550-599				15,934
500-549				11,309
Under 500				3,068
Total				1,020,104
Accrued interest included in total	[1]			4,178
Mortgage [Member] | Residential Fixed Rate Mortgage Loans [Member]
Sale of Mortgage Loans [Abstract]
Proceeds from sale of loans			2,400
Gain on sale of loans			$ 70
Mortgage [Member] | 1-4 Family Owner Occupied - Jumbo [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				61,077
750-799				223,177
700-749				101,086
650-699				40,296
600-649				11,146
550-599				0
500-549				3,396
Under 500				0
Total				440,178
Accrued interest included in total				1,301
Mortgage [Member] | 1-4 Family Owner Occupied - Non-jumbo [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				40,187
750-799				70,642
700-749				75,489
650-699				44,344
600-649				18,519
550-599				11,021
500-549				5,129
Under 500				2,242
Total				267,573
Accrued interest included in total				1,641
Mortgage [Member] | 1-4 Non-owner Occupied [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				25,468
750-799				82,124
700-749				30,326
650-699				13,182
600-649				4,303
550-599				2,388
500-549				1,580
Under 500				405
Total				159,776
Accrued interest included in total				587
Mortgage [Member] | 1-4 Family - 2nd Lien [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				12,490
750-799				42,138
700-749				22,962
650-699				11,269
600-649				2,703
550-599				1,608
500-549				1,012
Under 500				348
Total				94,530
Accrued interest included in total				373
Mortgage [Member] | Resort Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				9,546
750-799				27,530
700-749				11,726
650-699				6,393
600-649				1,670
550-599				917
500-549				192
Under 500				73
Total				58,047
Accrued interest included in total				276
Installment [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				70,608
750-799				257,091
700-749				96,961
650-699				40,121
600-649				7,118
550-599				2,511
500-549				1,392
Under 500				210
Unknown				510
Total				476,522
Accrued interest included in total	[1]			1,185
Installment [Member] | Boat Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				32,231
750-799				123,689
700-749				38,223
650-699				10,189
600-649				2,083
550-599				661
500-549				342
Under 500				95
Unknown				0
Total				207,513
Accrued interest included in total				572
Installment [Member] | Recreational Vehicle Lending [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				29,223
750-799				95,890
700-749				33,476
650-699				8,794
600-649				1,305
550-599				551
500-549				283
Under 500				52
Unknown				0
Total				169,574
Accrued interest included in total				457
Installment [Member] | Other [Member]
Loan ratings/credit scores by loan class [Abstract]
800 and above				9,154
750-799				37,512
700-749				25,262
650-699				21,138
600-649				3,730
550-599				1,299
500-549				767
Under 500				63
Unknown				510
Total				99,435
Accrued interest included in total				$ 156

[1] Beginning January 1, 2021, calculation is based on CECL methodology. Prior to January 1, 2021, calculation was based on the probable incurred loss methodology.