Per Share Data (Computations of Basic Earnings Per Share and Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic Earnings per Share:
Net Income	$ 6,483	$ 6,292	$ 18,824	$ 17,861
Weighted Average Shares Outstanding	12,666,780	12,628,335	12,658,403	12,618,863
Basic Earnings per Share	$ 0.51	$ 0.50	$ 1.49	$ 1.42
Diluted Earnings per Share:
Net Income	$ 6,483	$ 6,292	$ 18,824	$ 17,861
Weighted Average Shares Outstanding	12,666,780	12,628,335	12,658,403	12,618,863
Potentially Dilutive Shares, Net	24,384	20,589	19,950	15,009
Diluted Weighted Average Shares Outstanding	12,691,164	12,648,924	12,678,353	12,633,872
Diluted Earnings per Share	$ 0.51	$ 0.50	$ 1.48	$ 1.41