Nature of Operations and Summary of Significant Accounting Policies (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Basic earnings per share
Net income	$ 5,170	$ 4,850	$ 4,910	$ 4,613	$ 3,522	$ 3,417	$ 3,093	$ 2,765	$ 19,543	$ 12,797	$ 10,455
Less: Preferred stock dividends and accretion of discount									481	1,325	1,406
Net income available to common shareholders	5,014	4,787	4,804	4,457	3,460	2,707	2,816	2,489	19,062	11,472	9,049
Weighted average common shares outstanding	8,617,466	8,503,475	7,434,537	7,422,860	7,421,544	7,414,043	7,406,624	7,387,072	7,974,241	7,407,258	7,373,405
Basic Earnings Per Share	$ 0.58	$ 0.56	$ 0.65	$ 0.60	$ 0.47	$ 0.37	$ 0.38	$ 0.34	$ 2.39	$ 1.55	$ 1.23
Diluted earnings per share
Net income available to common shareholders									$ 19,062	$ 11,472	$ 9,049
Weighted average common shares outstanding	8,617,466	8,503,475	7,434,537	7,422,860	7,421,544	7,414,043	7,406,624	7,387,072	7,974,241	7,407,258	7,373,405
Effect of dilutive securities:
Warrants									245,514	161,922	90,981
Weighted average shares outstanding	8,964,315	8,838,659	7,728,519	7,598,490	7,576,052	7,596,570	7,598,180	7,612,144	8,271,177	7,588,394	7,502,846
Diluted Earnings Per Share	$ 0.56	$ 0.54	$ 0.62	$ 0.59	$ 0.46	$ 0.36	$ 0.37	$ 0.33	$ 2.30	$ 1.51	$ 1.21
Restricted stock [Member]
Effect of dilutive securities:
Effect of dilutive securities									23,181	4,361	33,041
Stock options [Member]
Effect of dilutive securities:
Effect of dilutive securities									28,241	14,853	5,418