Guarantees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Commitments to Extend Credit, Nominal Amount	$ 315,256	$ 296,442
Standby Letters of Credit, Nominal Amount	3,526	3,445
Commitments to Extend Credit, Fair Value	0	0
Fair Value Disclosure, Letters of Credit Outstanding, Amount	$ 23	$ 30
Minimum [Member]
Guarantor Obligations [Line Items]
Letter of Credit, Fee Percentage	1.00%
Maximum [Member]
Guarantor Obligations [Line Items]
Letter of Credit, Fee Percentage	3.00%