Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic Net Income per Common Share Available to Common Stockholders [Abstract]
Net income	$ 3,910,000	$ 3,647,000	$ 11,103,000	$ 10,516,000
Preferred stock dividends	(1,104,000)	(1,104,000)	(3,313,000)	(3,148,000)
Net income available to common stockholders	2,806,000	2,543,000	7,790,000	7,368,000
Weighted average common shares outstanding	5,935,383	6,030,053	5,947,476	6,025,255
Basic earnings per common share	$ 0.47	$ 0.42	$ 1.31	$ 1.22
Diluted Net Income per Common Share Available to Common Stockholders [Abstract]
Net income available to common stockholders	2,806,000	2,543,000	7,790,000	7,368,000
Effect of assumed preferred stock conversion	0		0	0
Net income applicable to diluted earnings per share	$ 2,806,000	$ 2,543,000	$ 7,790,000	$ 7,368,000
Weighted average common shares outstanding	5,935,383	6,030,053	5,947,476	6,025,255
Dilutive potential common shares [Abstract]
Assumed conversion of stock options	2,151	10,954	2,864	5,355
Restricted stock awarded	9,329	135	9,329	275
Assumed conversion of preferred stock	0	0	0	0
Dilutive potential common shares	11,480	11,089	12,193	5,630
Diluted weighted average common shares outstanding	5,946,863	6,041,142	5,959,669	6,030,885
Diluted net income per common share available to common stockholders	$ 0.47	$ 0.42	$ 1.31	$ 1.22
Stock options to purchase shares of common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share (in shares)	130,500	108,125	130,500	108,125
Average dilutive potential common shares associated with convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share (in shares)	2,494,801	2,490,079	2,494,801	2,222,967