Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Loss on tax credit investments		$ (3,997)	$ (3,022)
Tax credit in non-interest income		2,843	2,117
Income tax benefit		5,209	1,923	$ 3,767
Valuation allowance		285	276
Net deferred tax asset for investment in a historic tax credits		454	636
Net deferred tax asset for pension and SERP plans		1,184	2,094
Unrecognized tax benefits		0	0	$ 0
Accrued income tax penalties and interest		$ 0	0
Marginal federal tax rate		35.00%
Income tax expense, change in tax rate		$ 2,000
Other comprehensive income (loss), tax effect reclass due to TCJA		631
Historic tax credit investments		1,182	454
Projected benefit obligation		1,400
Minimum [Member]
Income Tax Contingency [Line Items]
Expected SERP benefit distribution		1,000
Maximum [Member]
Income Tax Contingency [Line Items]
Limit deductibility of executive compensation		1,000
Scenario, Plan [Member]
Income Tax Contingency [Line Items]
Marginal federal tax rate	21.00%
Pension And SERP Plans [Member]
Income Tax Contingency [Line Items]
Valuation allowance		114
Historic Structure In New York State [Member]
Income Tax Contingency [Line Items]
Tax credit in non-interest income		2,843	2,117
Income tax benefit		(1,869)	(1,413)
Valuation allowance		$ 171
Percentage of qualified rehabilitation expenses		20.00%
QRE period		5 years
Net income on HRTC investments		$ 715	$ 508
State [Member] | New York State Division of Taxation and Finance [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination		2015
State [Member] | New York State Division of Taxation and Finance [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination		2016
Federal [Member] | IRS [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination		2014
Federal [Member] | IRS [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination		2016