Loans (Analysis of Loan Servicing Rights) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loan Servicing Rights [Roll Forward]
Beginning balance	$ 3,493	$ 3,348	$ 2,989
Loan servicing rights capitalized	1,104	1,412	1,406
Amortization	(984)	(1,267)	(1,047)
Decrease in impairment reserve	0	0	0
Ending balance	3,613	3,493	3,348
Valuation Allowance [Roll Forward]
Beginning balance	0	(1)	(2)
Loan servicing rights capitalized	0	0	0
Amortization	0	0	0
Decrease in impairment reserve	0	1	1
Ending balance	0	0	(1)
Total Loan Servicing Rights [Roll Forward]
Beginning Balance	3,493	3,347	2,987
Loan servicing rights capitalized	1,104	1,412	1,406
Amortization	(984)	(1,267)	(1,047)
Decrease in impairment reserve	0	1	1
Ending balance	$ 3,613	$ 3,493	$ 3,347