Earnings Per Common Share (Calculation of Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 9,298	$ 7,421
Dividends and undistributed earnings allocated to participating securities	(41)	(39)
Net income applicable to common shareholders	$ 9,257	$ 7,382
Weighted average common shares outstanding - basic	16,626	16,401
Dilutive effect of common stock equivalents	174	48
Weighted average common shares outstanding - diluted	16,800	16,449
Basic earnings per common share	$ 0.56	$ 0.45
Diluted earnings per common share	$ 0.55	$ 0.45
Antidilutive common stock equivalents	55	336