Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets [Abstract]
Allowance for loan and lease losses	$ 2,843	$ 2,699
Net operating loss carryforward	20,712	22,546
Security writedowns	1,085	1,020
OREO writedowns	94	139
Investment in partnerships	1,920	1,698
Pension obligations	3,782	3,858
Deferred Tax Assets, Other Comprehensive Loss	1,407	1,250
Unrealized losses on debt securities	389	165
Share-based compensation cost	57	83
Non-accrual interest	203	366
Capital loss carryover	1,258	1,618
Charitable contribution carryovers	12	24
Employee bonuses	238	184
Accrued liabilities	105	181
Alternative minimum tax credit carryforward	426	302
Derivative Instruments	168	189
Other	73	311
Deferred tax assets before valuation allowance	34,772	36,633
Deferred Tax Assets, Net of Valuation Allowance, Total	8,188	6,060
Deferred tax liabilities [Abstract]
Penalties on delinquent tax certificates	25	35
Increase associated with equity investments	308
Unrealized gains on AFS equity securities		151
Prepaid deductions	121	43
Other	153	114
Total deferred tax liabilities	299	343
Less valuation allowance	(26,600)	(30,600)
Net deferred tax assets, included in other assets	7,889	5,717
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	4,000
Valuation Allowance AOCI
Deferred tax liabilities [Abstract]
Less valuation allowance	(1,407)	(1,099)
Valuation Allowance Others
Deferred tax liabilities [Abstract]
Less valuation allowance	$ (25,177)	$ (29,474)