Loans, Impaired Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Impaired loans with no allocated allowance for loan losses [Abstract]
TDR	$ 347		$ 347		$ 349
Non - TDR	2,402		2,402		175
Impaired loans with an allocated allowance for loan losses [Abstract]
TDR - allowance based on collateral	2,366		2,366		2,482
TDR - allowance based on present value cash flow	56,599		56,599		62,113
Non - TDR - allowance based on collateral	168		168		148
Total impaired loans	61,882		61,882		65,267
Amount of allowance for loan losses allocated [Abstract]
TDR - allowance based on collateral	692		692		684
TDR - allowance based on present value cash flow	5,335		5,335		6,089
Non - TDR - allowance based on collateral	75		75		66
Total amount of allowance for loan losses allocated	6,102		6,102		6,839
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	2,752		2,752		527
Unpaid Principal Balance, with no related allowance for loan losses recorded	3,341		3,341		1,087
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	59,407		59,407		65,017
Unpaid Principal Balance, with an allowance for loan losses recorded	61,248		61,248		67,289
With an allowance for loan losses recorded	62,159		62,159		65,544
Unpaid Principal Balance	64,589		64,589		68,376
Related Allowance	6,102		6,102		6,839
Accrued interest included in recorded investment	277		277		277
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	2,949	$ 573	1,744	$ 1,103
Interest Income Recognized, with no related allowance for loan losses recorded	17	17	44	37
Average Recorded Investment, with an allowance for loan losses recorded	60,330	69,775	62,299	72,397
Interest Income Recognized, with an allowance for loan losses recorded	770	810	2,308	2,524
Average Recorded Investment	63,279	70,348	64,043	73,500
Interest Income Recognized	787	827	2,352	2,561
Commercial [Member] | Income Producing - Real Estate [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	0		0		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	4,829		4,829		5,195
Unpaid Principal Balance, with an allowance for loan losses recorded	4,808		4,808		5,347
With an allowance for loan losses recorded	4,829		4,829		5,195
Unpaid Principal Balance	4,808		4,808		5,347
Related Allowance	307		307		347
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	222
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	4,968	7,311	5,077	7,525
Interest Income Recognized, with an allowance for loan losses recorded	64	91	202	300
Average Recorded Investment	4,968	7,311	5,077	7,747
Interest Income Recognized	64	91	202	300
Commercial [Member] | Land, Land Development and Construction - Real Estate [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	2,402		2,402		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	2,402		2,402		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	152		152		166
Unpaid Principal Balance, with an allowance for loan losses recorded	152		152		194
With an allowance for loan losses recorded	2,554		2,554		166
Unpaid Principal Balance	2,554		2,554		194
Related Allowance	4		4		9
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	2,402	0	1,201	8
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	153	171	157	187
Interest Income Recognized, with an allowance for loan losses recorded	3	2	7	6
Average Recorded Investment	2,555	171	1,358	195
Interest Income Recognized	3	2	7	6
Commercial [Member] | Commercial and Industrial [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	347		347		524
Unpaid Principal Balance, with no related allowance for loan losses recorded	347		347		549
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	1,984		1,984		2,535
Unpaid Principal Balance, with an allowance for loan losses recorded	2,133		2,133		2,651
With an allowance for loan losses recorded	2,331		2,331		3,059
Unpaid Principal Balance	2,480		2,480		3,200
Related Allowance	416		416		481
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	425	445	472	808
Interest Income Recognized, with no related allowance for loan losses recorded	7	8	20	16
Average Recorded Investment, with an allowance for loan losses recorded	2,264	2,878	2,391	3,488
Interest Income Recognized, with an allowance for loan losses recorded	24	26	90	98
Average Recorded Investment	2,689	3,323	2,863	4,296
Interest Income Recognized	31	34	110	114
Mortgage [Member] | 1-4 Family [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	2		2		2
Unpaid Principal Balance, with no related allowance for loan losses recorded	447		447		469
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	34,656		34,656		36,848
Unpaid Principal Balance, with an allowance for loan losses recorded	36,169		36,169		38,480
With an allowance for loan losses recorded	34,658		34,658		36,850
Unpaid Principal Balance	36,616		36,616		38,949
Related Allowance	3,126		3,126		3,454
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	121	127	70	64
Interest Income Recognized, with no related allowance for loan losses recorded	9	7	18	16
Average Recorded Investment, with an allowance for loan losses recorded	34,731	38,533	35,549	39,716
Interest Income Recognized, with an allowance for loan losses recorded	458	462	1,347	1,420
Average Recorded Investment	34,852	38,660	35,619	39,780
Interest Income Recognized	467	469	1,365	1,436
Mortgage [Member] | Resort Lending [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	0		0		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	13,934		13,934		15,978
Unpaid Principal Balance, with an allowance for loan losses recorded	13,972		13,972		16,046
With an allowance for loan losses recorded	13,934		13,934		15,978
Unpaid Principal Balance	13,972		13,972		16,046
Related Allowance	2,017		2,017		2,210
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	14,276	16,175	15,027	16,485
Interest Income Recognized, with an allowance for loan losses recorded	161	153	475	464
Average Recorded Investment	14,276	16,175	15,027	16,485
Interest Income Recognized	161	153	475	464
Mortgage [Member] | Home Equity - 1st Lien [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	0		0		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	66		66		173
Unpaid Principal Balance, with an allowance for loan losses recorded	65		65		236
With an allowance for loan losses recorded	66		66		173
Unpaid Principal Balance	65		65		236
Related Allowance	3		3		43
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	67	201	115	218
Interest Income Recognized, with an allowance for loan losses recorded	1	1	4	5
Average Recorded Investment	67	201	115	218
Interest Income Recognized	1	1	4	5
Mortgage [Member] | Home Equity - 2nd Lien [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	34		34		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	157		157		178
Unpaid Principal Balance, with an allowance for loan losses recorded	156		156		213
With an allowance for loan losses recorded	157		157		178
Unpaid Principal Balance	190		190		213
Related Allowance	9		9		18
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	157	180	167	217
Interest Income Recognized, with an allowance for loan losses recorded	2	2	5	5
Average Recorded Investment	157	180	167	217
Interest Income Recognized	2	2	5	5
Installment [Member] | Home Equity - 1st Lien [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	1		1		1
Unpaid Principal Balance, with no related allowance for loan losses recorded	90		90		69
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	1,520		1,520		1,667
Unpaid Principal Balance, with an allowance for loan losses recorded	1,640		1,640		1,804
With an allowance for loan losses recorded	1,521		1,521		1,668
Unpaid Principal Balance	1,730		1,730		1,873
Related Allowance	97		97		108
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	1	1	1	1
Interest Income Recognized, with no related allowance for loan losses recorded	1	1	5	4
Average Recorded Investment, with an allowance for loan losses recorded	1,545	1,808	1,595	1,874
Interest Income Recognized, with an allowance for loan losses recorded	27	40	81	107
Average Recorded Investment	1,546	1,809	1,596	1,875
Interest Income Recognized	28	41	86	111
Installment [Member] | Home Equity - 2nd Lien [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	0		0		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	1,626		1,626		1,793
Unpaid Principal Balance, with an allowance for loan losses recorded	1,644		1,644		1,805
With an allowance for loan losses recorded	1,626		1,626		1,793
Unpaid Principal Balance	1,644		1,644		1,805
Related Allowance	93		93		140
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	1,679	2,058	1,728	2,210
Interest Income Recognized, with an allowance for loan losses recorded	24	26	76	96
Average Recorded Investment	1,679	2,058	1,728	2,210
Interest Income Recognized	24	26	76	96
Installment [Member] | Boat Lending [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	5		5		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	0		0		1
Unpaid Principal Balance, with an allowance for loan losses recorded	0		0		5
With an allowance for loan losses recorded	0		0		1
Unpaid Principal Balance	5		5		5
Related Allowance	0		0		1
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	1	1	1	1
Interest Income Recognized, with an allowance for loan losses recorded	0	0	0	0
Average Recorded Investment	1	1	1	1
Interest Income Recognized	0	0	0	0
Installment [Member] | Recreational Vehicle Lending [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	0		0		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	81		81		90
Unpaid Principal Balance, with an allowance for loan losses recorded	81		81		90
With an allowance for loan losses recorded	81		81		90
Unpaid Principal Balance	81		81		90
Related Allowance	4		4		5
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	0	0	0
Average Recorded Investment, with an allowance for loan losses recorded	83	98	86	103
Interest Income Recognized, with an allowance for loan losses recorded	1	1	3	4
Average Recorded Investment	83	98	86	103
Interest Income Recognized	1	1	3	4
Installment [Member] | Other [Member]
Impaired Loans by class [Abstract]
Recorded Investment, with no related allowance for loan losses recorded	0		0		0
Unpaid Principal Balance, with no related allowance for loan losses recorded	16		16		0
With no related allowance for loan losses recorded	0		0		0
Recorded Investment, with an allowance for loan losses recorded	402		402		393
Unpaid Principal Balance, with an allowance for loan losses recorded	428		428		418
With an allowance for loan losses recorded	402		402		393
Unpaid Principal Balance	444		444		418
Related Allowance	26		26		$ 23
Average recorded investment in and interest income earned on impaired loans by class [Abstract]
Average Recorded Investment, with no related allowance for loan losses recorded	0	0	0	0
Interest Income Recognized, with no related allowance for loan losses recorded	0	1	1	1
Average Recorded Investment, with an allowance for loan losses recorded	406	361	406	373
Interest Income Recognized, with an allowance for loan losses recorded	5	6	18	19
Average Recorded Investment	406	361	406	373
Interest Income Recognized	$ 5	$ 7	$ 19	$ 20