Earnings Per Common Share (Calculation of Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]
Net income	$ 36,153	$ 35,074	$ 29,724
Dividends and undistributed earnings allocated to participating securities	(155)	(160)	(112)
Net income applicable to common shareholders	$ 35,998	$ 34,914	$ 29,612
Weighted average common shares outstanding - basic (in shares)	16,506	16,358	16,254
Dilutive effect of common stock equivalents (in shares)	158	43	30
Weighted average common shares outstanding - diluted (in shares)	16,664	16,401	16,284
Basic earnings per common share (in dollars per share)	$ 2.18	$ 2.13	$ 1.82
Diluted earnings per common share (in dollars per share)	$ 2.16	$ 2.13	$ 1.82
Antidilutive common stock equivalents	23	357	371