Loans and Allowance for Loan Losses - Internal Risk Rating Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	$ 1,076,782	$ 1,052,865	$ 1,075,606
Commercial
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	753,260	757,516	753,798
Commercial | Commercial Business
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	372,238	387,466
Commercial | Commercial Real Estate
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	270,547	271,460
Commercial | Acquisition & Development
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	110,475	98,590
Residential
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	244,591	215,452	236,643
Home Equity
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	65,170	65,386	68,318
Consumer
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	13,761	14,511	$ 16,847
Pass
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	1,023,532	1,001,066
Pass | Commercial
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	704,563	709,357
Pass | Commercial | Commercial Business
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	361,762	377,631
Pass | Commercial | Commercial Real Estate
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	239,998	240,851
Pass | Commercial | Acquisition & Development
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	102,803	90,875
Pass | Residential
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	241,832	212,869
Pass | Home Equity
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	63,813	64,706
Pass | Consumer
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	13,324	14,134
Special Mention
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	35,805	33,726
Special Mention | Commercial
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	32,332	31,178
Special Mention | Commercial | Commercial Business
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	3,658	2,933
Special Mention | Commercial | Commercial Real Estate
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	26,786	26,340
Special Mention | Commercial | Acquisition & Development
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	1,888	1,905
Special Mention | Residential
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	1,909	1,664
Special Mention | Home Equity
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	1,220	582
Special Mention | Consumer
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	344	302
Substandard
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	13,604	13,847
Substandard | Commercial
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	12,866	12,949
Substandard | Commercial | Commercial Business
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	6,774	6,833
Substandard | Commercial | Commercial Real Estate
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	3,509	3,532
Substandard | Commercial | Acquisition & Development
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	2,583	2,584
Substandard | Residential
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	570	787
Substandard | Home Equity
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	137	98
Substandard | Consumer
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	31	13
Doubtful
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	3,841	4,226
Doubtful | Commercial
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	3,499	4,032
Doubtful | Commercial | Commercial Business
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	44	69
Doubtful | Commercial | Commercial Real Estate
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	254	737
Doubtful | Commercial | Acquisition & Development
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	3,201	3,226
Doubtful | Residential
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	280	132
Doubtful | Home Equity
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	0	0
Doubtful | Consumer
Classes of the loan portfolio summarized by credit quality indicators:
Total loans	$ 62	$ 62