CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities:
Net income (loss)	$ 43,737,367	$ (24,300,492)	$ (35,499,967)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net amortization/accretion of premium/discount on securities	7,702,123	5,667,069	4,735,074
Depreciation and amortization	10,950,434	11,500,075	10,804,664
Provision for loan losses	21,797,613	53,695,454	116,758,231
Gains on sales of investment securities, net	(960,763)	(2,623,674)	(6,462,241)
Gain on loan sales, net	(4,155,137)	(4,085,657)	(4,928,542)
Stock-based compensation expense	5,018,294	3,981,013	3,251,003
Deferred tax (benefit) expense	(23,395,052)	17,822,071	(24,645,791)
Losses on other real estate and other investments	14,081,857	25,459,851	11,987,395
Excess tax benefit from stock compensation	(13,819)	(16,776)	(53,538)
Mortgage loans held for sale:
Loans originated	(394,020,876)	(444,833,043)	(626,402,322)
Loans sold	378,996,474	445,227,014	644,098,081
Increase in other assets	42,346,579	27,366,049	16,214,893
Increase (decrease) in other liabilities	11,004,661	14,730,158	(19,551,401)
Net cash provided by operating activities	113,089,755	129,589,112	90,305,539
Activities in available-for-sale securities:
Purchases	(268,141,975)	(548,916,132)	(721,011,285)
Sales	166,415,738	146,082,535	346,895,583
Maturities, prepayments and calls	233,622,196	322,414,157	284,950,245
Activities in held-to-maturity securities:
Sales	0	954,388	0
Maturities, prepayments and calls	1,975,000	1,235,612	3,960,000
Increase (decrease) in loans, net	(144,581,478)	194,133,354	(329,573,695)
Purchases of premises and equipment and software	(2,031,265)	(9,587,707)	(19,175,840)
Other investments	(407,504)	(1,878,676)	(6,859,089)
Net cash (used in) provided by investing activities	(13,149,288)	104,437,531	(440,814,081)
Financing activities:
Net (decrease) increase in deposits	(178,660,721)	9,688,996	290,833,250
Net (decrease) increase in repurchase agreements	(14,702,967)	(129,170,717)	91,167,303
Net decrease in Federal funds purchased	0	0	(71,643,000)
Federal Home Loan Bank:
Issuances	215,000,000	90,000,000	70,000,000
Payments	(110,236,705)	(181,149,655)	(41,153,298)
Net increase (decrease) in borrowings under lines of credit	0	0	(18,000,000)
Exercise of common stock warrants	0	285,000	300,000
Exercise of common stock options and stock appreciation rights	864,805	3,037,064	666,034
Excess tax benefit from stock compensation	13,819	16,776	53,538
Preferred dividends paid	(4,891,839)	(4,750,000)	(4,393,751)
Proceeds from the sale of common stock, net of expenses	0	0	109,027,785
Repurchase of preferred shares outstanding	(23,750,000)	0	0
Net cash (used in) provided by financing activities	(116,363,608)	(212,042,536)	426,857,861
Net (decrease) increase in cash and cash equivalents	(16,423,141)	21,984,107	76,349,319
Cash and cash equivalents, beginning of year	188,586,181	166,602,074	90,252,755
Cash and cash equivalents, end of year	$ 172,163,040	$ 188,586,181	$ 166,602,074