Earnings Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Basic Net Income per Common Share Available to Common Stockholders [Abstract]
Net income	$ 3,665,000	$ 3,479,000	$ 7,193,000	$ 6,869,000
Preferred stock dividends	(1,105,000)	(1,105,000)	(2,209,000)	(2,044,000)
Net income available to common stockholders	2,560,000	2,374,000	4,984,000	4,825,000
Weighted average common shares outstanding	5,951,981	6,025,802	5,953,623	6,022,830
Basic earnings per common share	$ 0.43	$ 0.39	$ 0.84	$ 0.80
Diluted Net Income per Common Share Available to Common Stockholders [Abstract]
Net income available to common stockholders	2,560,000	2,374,000	4,984,000	4,825,000
Effect of assumed preferred stock conversion	0		0	0
Net income applicable to diluted earnings per share	$ 2,560,000	$ 2,374,000	$ 4,984,000	$ 4,825,000
Weighted average common shares outstanding	5,951,981	6,025,802	5,953,623	6,022,830
Dilutive potential common shares [Abstract]
Assumed conversion of stock options	1,118	8,826	1,124	8,504
Restricted stock awarded	9,027	413	9,027	331
Assumed conversion of preferred stock	0	0	0	0
Dilutive potential common shares	10,145	9,239	10,151	8,835
Diluted weighted average common shares outstanding	5,962,126	6,035,041	5,963,774	6,031,665
Diluted net income per common share available to common stockholders	$ 0.43	$ 0.39	$ 0.84	$ 0.80
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)	104,750	196,220	104,750	196,220
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	2,092,411	2,494,801	2,087,943