Earnings Per Common Share (Calculation of Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income	$ 10,538	$ 9,960	$ 29,633	$ 26,364
Less dividends and undistributed earnings allocated to participating securities	(32)	(37)	(106)	(115)
Net income applicable to common shareholders	10,506	9,923	29,527	26,249
Weighted average common shares outstanding - basic	16,714,000	16,563,000	16,673,000	16,473,000
Basic earnings per common share	$ 0.63	$ 0.60	$ 1.77	$ 1.59
Less dividends and undistributed earnings allocated to participating securities	(32)	(37)	(106)	(115)
Net Income (Loss) Available to Common Stockholders, Diluted	$ 10,506	$ 9,923	$ 29,527	$ 26,249
Dilutive effect of common stock equivalents	141,000	133,000	159,000	127,000
Weighted average common shares outstanding - diluted	16,855,000	16,696,000	16,832,000	16,600,000
Diluted earnings per common share	$ 0.62	$ 0.59	$ 1.75	$ 1.58
Antidilutive common stock equivalents	52,426	0	53,853	7,165