Stock-Based Compensation (Details 1) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of the restricted stock transactions
Shares, Outstanding	106,789	89,832	50,062
Shares, Granted	48,471	55,081	56,756
Shares, Vested	(51,368)	(36,142)	(16,529)
Shares, Forfeited/canceled/expired	(630)	(1,982)	(457)
Shares, Outstanding	103,262	106,789	89,832
Weighted Average Grant Date Fair Value, Outstanding	$ 40.28	$ 41.20	$ 46.51
Weighted Average Grant Date Fair Value, Granted	48.60	40.09	38.11
Weighted Average Grant Date Fair Value, Vested	41.20	42.11	46.51
Weighted Average Grant Date Fair Value, Forfeited/canceled/expired	38.83	43.62	46.51
Weighted Average Grant Date Fair Value, Outstanding	$ 43.73	$ 40.28	$ 41.20
Weighted average remaining contractual life (in years)	3 years 4 months 24 days