Loans, Troubled Debt Restructurings Segregated by Class (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($) Loan	Sep. 30, 2017 USD ($) Loan	Sep. 30, 2018 USD ($) Loan	Sep. 30, 2017 USD ($) Loan	Dec. 31, 2017 USD ($) Loan
Troubled Debt Restructurings Segregated by Class [Abstract]
Number of Loans | Loan	7	7	36	25	43
Post-Modification Outstanding Balance	$ 2,692	$ 397	$ 7,157	$ 2,722	$ 5,547
Commitment to extend additional credit on loans modified in TDRs	$ 42		$ 42
Defaulted restructured loans, number of loans | Loan	3	3	5	3
Defaulted restructured loans, recorded balance	$ 153	$ 1,807	$ 195	$ 1,807
Term Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	2,292	397	5,759	2,280	5,105
Rate Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	0	0	0	0	0
Combination [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	$ 400	$ 0	$ 1,398	$ 442	$ 442
Commercial [Member] | Construction [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Number of Loans | Loan			4	2	2
Post-Modification Outstanding Balance			$ 458	$ 114	$ 114
Defaulted restructured loans, number of loans | Loan	2	0	2	0
Defaulted restructured loans, recorded balance	$ 147	$ 0	$ 147	$ 0
Commercial [Member] | Construction [Member] | Term Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance			443	0	0
Commercial [Member] | Construction [Member] | Rate Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance			0	0	0
Commercial [Member] | Construction [Member] | Combination [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance			$ 15	$ 114	$ 114
Commercial [Member] | Real Estate [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Number of Loans | Loan	6	6	23	11	15
Post-Modification Outstanding Balance	$ 2,428	$ 295	$ 5,970	$ 1,066	$ 2,391
Defaulted restructured loans, number of loans | Loan	0	2	1	2
Defaulted restructured loans, recorded balance	$ 0	$ 961	$ 17	$ 961
Commercial [Member] | Real Estate [Member] | Term Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	2,028	295	4,587	874	2,199
Commercial [Member] | Real Estate [Member] | Rate Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	0	0	0	0	0
Commercial [Member] | Real Estate [Member] | Combination [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	$ 400	$ 0	$ 1,383	$ 192	$ 192
Commercial [Member] | Other [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Number of Loans | Loan		1	8	10	22
Post-Modification Outstanding Balance		$ 102	$ 465	$ 373	$ 1,208
Defaulted restructured loans, number of loans | Loan	1	0	2	0
Defaulted restructured loans, recorded balance	$ 6	$ 0	$ 31	$ 0
Commercial [Member] | Other [Member] | Term Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance		102	465	237	1,072
Commercial [Member] | Other [Member] | Rate Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance		0	0	0	0
Commercial [Member] | Other [Member] | Combination [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance		$ 0	$ 0	$ 136	$ 136
Residential [Member] | Construction [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Number of Loans | Loan				1	1
Post-Modification Outstanding Balance				$ 846	$ 846
Residential [Member] | Construction [Member] | Term Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance				846	846
Residential [Member] | Construction [Member] | Rate Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance				0	0
Residential [Member] | Construction [Member] | Combination [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance				$ 0	$ 0
Residential [Member] | Real Estate [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Number of Loans | Loan	1		1	1	3
Post-Modification Outstanding Balance	$ 264		$ 264	$ 323	$ 988
Defaulted restructured loans, number of loans | Loan	0	1	0	1
Defaulted restructured loans, recorded balance	$ 0	$ 846	$ 0	$ 846
Residential [Member] | Real Estate [Member] | Term Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	264		264	323	988
Residential [Member] | Real Estate [Member] | Rate Modification [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	0		0	0	0
Residential [Member] | Real Estate [Member] | Combination [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Post-Modification Outstanding Balance	$ 0		$ 0	$ 0	$ 0