Loans and Related Allowance for Loan Losses (Average of Impaired Loans and Related Interest Income by Loan Portfolio Class) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Impaired [Line Items]
Average Investment	$ 20,245	$ 30,322	$ 21,467	$ 27,734
Interest income recognized on an accrual basis	122	219	368	506
Interest income recognized on a cash basis	1	4	8	12
Commercial real estate- non owner-occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	6,144	10,210	6,255	5,903
Interest income recognized on an accrual basis	6	78	18	125
Interest income recognized on a cash basis	0	0	0	0
Commercial real estate- all other CRE [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	7,308	11,191	8,314	12,142
Interest income recognized on an accrual basis	52	55	157	135
Interest income recognized on a cash basis	0	4	0	8
Acquisition and development- 1-4 family residential construction [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	582	582	582	641
Interest income recognized on an accrual basis	6	6	18	21
Interest income recognized on a cash basis	0	0	0	0
Acquisition and development- All other A&D [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	1,812	1,997	1,851	2,933
Interest income recognized on an accrual basis	23	24	68	72
Interest income recognized on a cash basis	0	0	0	0
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	496	1,119	393	1,095
Interest income recognized on an accrual basis	3	13	9	32
Interest income recognized on a cash basis	0	0	0	0
Residential mortgage- term [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	3,654	4,916	3,836	4,718
Interest income recognized on an accrual basis	32	43	98	121
Interest income recognized on a cash basis	1	0	8	4
Residential mortgage- home equity [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	249	307	236	302
Interest income recognized on an accrual basis	0	0	0	0
Interest income recognized on a cash basis	0	0	0	0
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Average Investment	0	0	0	0
Interest income recognized on an accrual basis	0	0	0	0
Interest income recognized on a cash basis	$ 0	$ 0	$ 0	$ 0

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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