Loans (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Allowance for loan losses:
Beginning Balance	$ 10,725	$ 10,434	$ 10,515	$ 9,860
Charge-offs	(219)	(253)	(963)	(469)
Recoveries	193	30	247	64
Provisions	40	224	940	980
Ending Balance	10,739	10,435	10,739	10,435
Commercial Real Estate Loans [Member]
Allowance for loan losses:
Beginning Balance	6,563	6,085	6,451	5,212
Charge-offs	(32)	(217)	(268)	(217)
Recoveries	2	4	8	13
Provisions	179	436	521	1,300
Ending Balance	6,712	6,308	6,712	6,308
Residential First Mortgage Loans [Member]
Allowance for loan losses:
Beginning Balance	737	1,300	1,144	1,406
Charge-offs	(2)		(115)
Provisions	(44)	(43)	(338)	(149)
Ending Balance	691	1,257	691	1,257
Residential Rentals Loans [Member]
Allowance for loan losses:
Beginning Balance	469	335	512	362
Charge-offs	(54)		(54)	(42)
Provisions	170	289	127	304
Ending Balance	585	624	585	624
Construction And Land Development Loans [Member]
Allowance for loan losses:
Beginning Balance	498	720	462	941
Charge-offs		(1)		(26)
Provisions	(203)	(73)	(167)	(269)
Ending Balance	295	646	295	646
Home Equity And Second Mortgage Loans [Member]
Allowance for loan losses:
Beginning Balance	104	112	162	138
Charge-offs		(13)	(7)	(14)
Recoveries	2	1	16	1
Provisions	71	28	6	3
Ending Balance	177	128	177	128
Commercial Loans [Member]
Allowance for loan losses:
Beginning Balance	1,203	814	1,013	794
Charge-offs	2		(86)
Recoveries	176		176	1
Provisions	(167)	(23)	111	(4)
Ending Balance	1,214	791	1,214	791
Consumer Loans [Member]
Allowance for loan losses:
Beginning Balance	7	5	7	3
Charge-offs	(1)		(2)	(2)
Provisions	(1)	2		6
Ending Balance	5	7	5	7
Commercial Equipment Loans [Member]
Allowance for loan losses:
Beginning Balance	1,144	1,063	764	1,004
Charge-offs	(132)	(22)	(431)	(168)
Recoveries	13	25	47	49
Provisions	35	(392)	680	(211)
Ending Balance	$ 1,060	$ 674	$ 1,060	$ 674