Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net Income	$ 26,534	$ 24,662	$ 23,360
Basic Shares, in Shares	13,391	13,281	13,242
Basic Earnings, in USD Per Share	$ 1.98	$ 1.86	$ 1.76
Dilutive Average Shares Attributable to Stock Options, in Shares	85	49	30
Weighted Average Shares - Diluted, in Shares	13,476	13,330	13,272
Diluted Earnings, In USD Per Share	$ 1.97	$ 1.85	$ 1.76