Quarterly Results of Operations (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Results of Operations [Abstract]
Interest Income	$ 13,943	$ 13,567	$ 13,258	$ 13,034	$ 13,313	$ 13,049	$ 12,731	$ 12,683	$ 12,893	$ 12,803	$ 12,744	$ 12,738	$ 53,802	$ 51,776	$ 51,178
Interest Expense	2,374	2,330	2,271	2,272	2,214	2,233	2,191	2,165	2,255	2,163	2,186	2,319	9,247	8,803	8,923
Net Interest Income	11,569	11,237	10,987	10,762	11,099	10,816	10,540	10,518	10,638	10,640	10,558	10,419	44,555	42,973	42,255
Provision for loan losses	250	250	150	200	125						500	350	850	125	850
Net Income Loss	$ 3,237	$ 3,482	$ 4,157	$ 2,365	$ 3,338	$ 3,225	$ 3,218	$ 2,481	$ 3,661	$ 2,751	$ 2,614	$ 2,020	13,241	12,262	$ 11,046
Net Income Available to Common Shareholders													$ 13,241	$ 12,262
Earnings per share, basic	$ 0.44	$ 0.48	$ 0.56	$ 0.32	$ 0.45	$ 0.44	$ 0.44	$ 0.34	$ 0.51	$ 0.38	$ 0.37	$ 0.28	$ 1.79	$ 1.66	$ 1.54
Earnings per share, diluted	$ 0.43	$ 0.47	$ 0.55	$ 0.31	$ 0.44	$ 0.43	$ 0.43	$ 0.33	$ 0.49	$ 0.37	$ 0.36	$ 0.27	$ 1.76	$ 1.62	$ 1.49