CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest income:
Loans, including fees	$ 154,748,491	$ 162,901,763	$ 162,271,036
Securities:
Taxable	23,971,787	30,306,189	35,056,848
Tax-exempt	7,394,134	7,916,596	6,540,653
Federal funds sold and other	2,232,423	2,223,816	1,847,661
Total interest income	188,346,835	203,348,364	205,716,198
Interest expense:
Deposits	30,588,033	49,856,815	63,128,940
Securities sold under agreements to repurchase	1,110,078	1,749,905	1,689,073
Federal Home Loan Bank advances and other borrowings	5,184,313	7,368,258	10,106,922
Total interest expense	36,882,424	58,974,978	74,924,935
Net interest income	151,464,411	144,373,386	130,791,263
Provision for loan losses	21,797,613	53,695,454	116,758,231
Net interest income after provision for loan losses	129,666,798	90,677,932	14,033,032
Noninterest income:
Service charges on deposit accounts	9,244,165	9,591,543	10,199,838
Investment services	6,246,414	5,050,105	4,181,101
Insurance sales commissions	3,999,153	3,864,340	4,025,839
Trust fees	2,999,731	2,872,490	2,590,997
Gains on mortgage loans sold, net	4,155,137	4,085,657	4,928,542
Net gain on sale of investment securities	960,763	2,623,674	6,462,241
Other noninterest income	10,334,847	8,227,237	7,263,068
Total noninterest income	37,940,210	36,315,046	39,651,626
Noninterest expense:
Salaries and employee benefits	74,424,851	64,628,991	56,709,814
Equipment and occupancy	19,986,976	21,077,223	18,056,080
Other real estate expense	17,431,926	29,210,197	14,257,005
Marketing and other business development	3,303,151	3,233,224	2,533,953
Postage and supplies	2,120,722	2,538,021	2,929,447
Amortization of intangibles	2,862,837	2,980,986	3,185,111
Other noninterest expense	18,976,865	23,214,670	20,906,040
Total noninterest expense	139,107,328	146,883,312	118,577,450
Income (loss) before income taxes	28,499,680	(19,890,334)	(64,892,792)
Income tax (benefit) expense	(15,237,687)	4,410,158	(29,392,825)
Net income (loss)	43,737,367	(24,300,492)	(35,499,967)
Preferred stock dividends	4,606,493	4,815,973	4,815,972
Accretion on preferred stock discount	2,058,146	1,326,049	1,113,986
Net income (loss) available to common stockholders	$ 37,072,728	$ (30,442,514)	$ (41,429,925)
Per share information:
Basic net income (loss) per common share available to common stockholders (in dollars per share)	$ 1.11	$ (0.93)	$ (1.46)
Diluted net income (loss) per common share available to common stockholders (in dollars per share)	$ 1.09	$ (0.93)	$ (1.46)
Weighted average common shares outstanding:
Basic (in shares)	33,420,015	32,789,871	28,395,618
Diluted (in shares)	34,060,228	32,789,871	28,395,618