Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Basic Net Income per Common Share Available to Common Stockholders [Abstract]
Net income	$ 3,647,000	$ 2,679,000	$ 10,516,000	$ 8,102,000
Preferred stock dividends	(1,104,000)	(919,000)	(3,148,000)	(2,637,000)
Net income available to common stockholders	2,543,000	1,760,000	7,368,000	5,465,000
Weighted average common shares outstanding, basic (in shares)	6,030,053	6,023,521	6,025,255	6,051,481
Basic earnings per share (in dollars per share)	$ 0.42	$ 0.29	$ 1.22	$ 0.90
Diluted Net Income per Common Share Available to Common Stockholders [Abstract]
Net income available to common stockholders	2,543,000	1,760,000	7,368,000	5,465,000
Effect of assumed preferred stock conversion	0	0	0	0
Net income applicable to diluted earnings per share	$ 2,543,000	$ 1,760,000	$ 7,368,000	$ 5,465,000
Weighted average common shares outstanding, basic (in shares)	6,030,053	6,023,521	6,025,255	6,051,481
Dilutive potential common shares [Abstract]
Assumed conversion of stock options (in shares)	10,954	11,769	5,355	12,415
Restricted stock awarded (in shares)	135	128	275	128
Assumed conversion of preferred stock (in shares)	0	0	0	0
Dilutive potential common shares (in shares)	11,089	11,897	5,630	12,543
Diluted weighted average common shares outstanding (in shares)	6,041,142	6,035,418	6,030,885	6,064,024
Diluted net income per common share available to common stockholders (in dollars per share)	$ 0.42	$ 0.29	$ 1.22	$ 0.90
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)	108,125	202,970	108,125	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)	2,490,079	2,078,788	2,222,967	1,960,390