Earnings Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Basic Net Income per Common Share Available to Common Stockholders [Abstract]
Net income	$ 3,479,000	$ 2,578,000	$ 6,869,000	$ 5,423,000
Preferred stock dividends	1,105,000	1,011,000	2,044,000	1,718,000
Net income available to common stockholders	2,374,000	1,567,000	4,825,000	3,705,000
Weighted average common shares outstanding, basic (in shares)	6,025,802	6,058,859	6,022,830	6,065,692
Basic earnings per share (in dollars per share)	$ 0.39	$ 0.26	$ 0.80	$ 0.61
Diluted Net Income per Common Share Available to Common Stockholders [Abstract]
Net income available to common stockholders	2,374,000	1,567,000	4,825,000	3,705,000
Net income applicable to diluted earnings per share	$ 2,374,000	$ 1,567,000	$ 4,825,000	$ 3,705,000
Weighted average common shares outstanding, basic (in shares)	6,025,802	6,058,859	6,022,830	6,065,692
Dilutive potential common shares [Abstract]
Assumed conversion of stock options (in shares)	8,826	12,722	8,504	12,742
Restricted stock awarded (in shares)	413	0	331	0
Dilutive potential common shares (in shares)	9,239	12,722	8,835	12,742
Diluted weighted average common shares outstanding (in shares)	6,035,041	6,071,581	6,031,665	6,078,434
Diluted net income per common share available to common stockholders (in dollars per share)	$ 0.39	$ 0.26	$ 0.80	$ 0.61
Stock options to purchase shares of common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share (in shares)	196,220	202,970	196,220	202,970
Average dilutive potential common shares associated with convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share (in shares)	2,092,411	1,950,933	2,087,943	1,882,586