Federal Income Taxes (Significant components of our deferred tax assets and liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets
Allowance for loan losses	$ 1,576	$ 1,582
Deferred directors' fees	2,758	2,549
Employee benefit plans	115	229
Core deposit premium and acquisition expenses	1,157	1,098
Net unrecognized actuarial loss on pension plan	1,531	1,708
Life insurance death benefit payable	804	804
Alternative minimum tax	717	650
Other	618	53
Total deferred tax assets	9,276	8,673
Deferred tax liabilities
Prepaid pension cost	809	890
Premises and equipment	115	166
Accretion on securities	58	55
Core deposit premium and acquisition expenses	1,403	1,289
Net unrealized gains on available-for-sale securities	418	2,252
Deferred Tax Assets, Derivative Instruments	84	0
Other	1,502	989
Total deferred tax liabilities	4,389	5,641
Net deferred tax assets	$ 4,887	$ 3,032