CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating activities:
Net income	$ 13,448,125	$ 8,364,954
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization/accretion of premium/discount on securities	988,811	1,971,889
Depreciation and amortization	2,432,535	2,660,347
Provision for loan losses	2,172,404	1,034,245
Gain on mortgage loans sold, net	(1,813,488)	(1,494,472)
Gain on sale of investment securities, net	0	(113,600)
Stock-based compensation expense	962,969	1,488,522
Deferred tax benefit	(698,661)	(1,831,027)
(Gains) losses on dispositions of other real estate and other investments	(866,306)	4,283,855
Excess tax benefit from stock compensation	(28,628)	(4,978)
Mortgage loans held for sale:
Loans originated	(107,845,659)	(105,694,598)
Loans sold	120,569,000	119,023,000
Decrease in other assets	3,050,703	15,794,855
Decrease in other liabilities	(8,339,670)	(3,128,767)
Net cash provided by operating activities	24,032,135	42,354,225
Activities in securities available-for-sale:
Purchases	(65,052,729)	(17,954,670)
Sales	0	14,359,785
Maturities, prepayments and calls	43,551,916	56,585,619
Activities in securities held-to-maturity:
Maturities, prepayments and calls	(75,868)	1,280,000
Increase in loans, net	(63,167,119)	(54,941,031)
Purchases of software, premises and equipment	(1,442,076)	(1,271,826)
Purchase of bank owned life insurance	(30,000,000)	0
Increase in other investments	(303,750)	(286,569)
Net cash used in investing activities	(116,489,626)	(2,228,692)
Financing activities:
Net decrease in deposits	(112,293,132)	(66,220,256)
Net increase (decrease) in securities sold under agreements to repurchase	14,432,033	(13,502,880)
Advances from Federal Home Loan Bank:
Issuances	240,000,000	215,000,000
Payments/maturities	(115,036,641)	(215,017,901)
Decrease in other borrowings	(625,000)	0
Exercise of common stock options and stock appreciation rights	222,200	405,438
Excess tax benefit from stock compensation	28,628	4,978
Preferred dividends paid	0	(890,624)
Net cash provided by (used in) financing activities	26,728,088	(80,221,245)
Net decrease in cash and cash equivalents	(65,729,403)	(40,095,712)
Cash and cash equivalents, beginning of period	165,288,669	172,163,040
Cash and cash equivalents, end of period	$ 99,559,266	$ 132,067,328