Loans and Allowance for Credit Losses (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Allowance for credit losses:
Beginning balance	$ 10,343	$ 9,781
Charge-offs	(210)	(527)
Recoveries	185	175
Net charge-offs	(25)	(352)
Provision	100	489
Ending balance	10,418	9,918
Commercial and Residential Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Allowance for credit losses:
Beginning balance	2,662	2,460
Charge-offs		(379)
Recoveries	3	9
Net charge-offs	3	(370)
Provision	(8)	451
Ending balance	2,657	2,541
Residential Portfolio Segment [Member]
Allowance for credit losses:
Beginning balance	2,353	2,284
Charge-offs	(123)	(138)
Recoveries	8	13
Net charge-offs	(115)	(125)
Provision	195	200
Ending balance	2,433	2,359
Commercial Real Estate Portfolio Segment [Member]
Allowance for credit losses:
Beginning balance	3,077	2,594
Recoveries	99	10
Net charge-offs	99	10
Provision	(119)	39
Ending balance	3,057	2,643
Commercial Portfolio Segment [Member]
Allowance for credit losses:
Beginning balance	1,949	2,241
Charge-offs	(81)
Recoveries	75	143
Net charge-offs	(6)	143
Provision	66	(226)
Ending balance	2,009	2,158
Consumer Portfolio Segment [Member]
Allowance for credit losses:
Beginning balance	302	202
Charge-offs	(6)	(10)
Net charge-offs	(6)	(10)
Provision	(34)	25
Ending balance	$ 262	$ 217