Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (6) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013 Factor Market Loan	Sep. 30, 2012	Sep. 30, 2013 Scale Factor Market Loan	Sep. 30, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			$ 78,738,000
Provision for loan losses, LHFI	(3,624,000)	3,358,000	(11,438,000)	7,301,000
Balance at end of period	68,632,000		68,632,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Total	68,632,000		68,632,000
Number of loan types for commercial portfolio	9		9
Number of unique qualitative factors used to analyze consumer loans	5		5
Number of risk rate factors for commercial loans	450		450
Minimum score for qualitative risk factor			0
Maximum score for qualitative risk factor			100
One time additional provision due to revision of methodology			1,400,000
Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			78,738,000	89,518,000
Loans charged-off			(10,173,000)	(22,547,000)
Recoveries			11,505,000	9,254,000
Net recoveries (charge-offs)			1,332,000	(13,293,000)
Provision for loan losses, LHFI			(11,438,000)	7,301,000
Balance at end of period	68,632,000	83,526,000	68,632,000	83,526,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	9,706,000	13,651,000	9,706,000	13,651,000
Collectively	58,926,000	69,875,000	58,926,000	69,875,000
Total	68,632,000	83,526,000	68,632,000	83,526,000
Loans Secured by Real Estate [Member] | Construction Land Development and Other Land Loans [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			21,838,000	27,220,000
Loans charged-off			(1,091,000)	(2,944,000)
Recoveries			2,561,000	0
Provision for loan losses, LHFI			(7,419,000)	(1,732,000)
Balance at end of period	15,889,000	22,544,000	15,889,000	22,544,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	957,000	4,829,000	957,000	4,829,000
Collectively	14,932,000	17,715,000	14,932,000	17,715,000
Total	15,889,000	22,544,000	15,889,000	22,544,000
Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			12,957,000	12,650,000
Loans charged-off			(839,000)	(3,238,000)
Recoveries			363,000	364,000
Provision for loan losses, LHFI			(3,723,000)	2,203,000
Balance at end of period	8,758,000	11,979,000	8,758,000	11,979,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	260,000	1,373,000	260,000	1,373,000
Collectively	8,498,000	10,606,000	8,498,000	10,606,000
Total	8,758,000	11,979,000	8,758,000	11,979,000
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			21,096,000	24,358,000
Loans charged-off			(572,000)	(5,409,000)
Recoveries			64,000	0
Provision for loan losses, LHFI			(1,828,000)	3,823,000
Balance at end of period	18,760,000	22,772,000	18,760,000	22,772,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	2,733,000	3,259,000	2,733,000	3,259,000
Collectively	16,027,000	19,513,000	16,027,000	19,513,000
Total	18,760,000	22,772,000	18,760,000	22,772,000
Loans Secured by Real Estate [Member] | Other Loans Secured by Real Estate [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			2,197,000	3,079,000
Loans charged-off			(910,000)	(1,602,000)
Recoveries			80,000	0
Provision for loan losses, LHFI			497,000	733,000
Balance at end of period	1,864,000	2,210,000	1,864,000	2,210,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	37,000	855,000	37,000	855,000
Collectively	1,827,000	1,355,000	1,827,000	1,355,000
Total	1,864,000	2,210,000	1,864,000	2,210,000
Commercial and Industrial Loans [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			14,319,000	15,868,000
Loans charged-off			(1,225,000)	(2,985,000)
Recoveries			2,190,000	2,123,000
Provision for loan losses, LHFI			2,004,000	3,428,000
Balance at end of period	17,288,000	18,434,000	17,288,000	18,434,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	5,393,000	2,995,000	5,393,000	2,995,000
Collectively	11,895,000	15,439,000	11,895,000	15,439,000
Total	17,288,000	18,434,000	17,288,000	18,434,000
Consumer Loans [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			3,087,000	3,656,000
Loans charged-off			(1,789,000)	(2,360,000)
Recoveries			3,561,000	4,189,000
Provision for loan losses, LHFI			(2,256,000)	(2,620,000)
Balance at end of period	2,603,000	2,865,000	2,603,000	2,865,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	2,000	4,000	2,000	4,000
Collectively	2,601,000	2,861,000	2,601,000	2,861,000
Total	2,603,000	2,865,000	2,603,000	2,865,000
Other Loans [Member] | Allowance for Loan Loses, LHFI [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			3,244,000	2,687,000
Loans charged-off			(3,747,000)	(4,009,000)
Recoveries			2,686,000	2,578,000
Provision for loan losses, LHFI			1,287,000	1,466,000
Balance at end of period	3,470,000	2,722,000	3,470,000	2,722,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	324,000	336,000	324,000	336,000
Collectively	3,146,000	2,386,000	3,146,000	2,386,000
Total	$ 3,470,000	$ 2,722,000	$ 3,470,000	$ 2,722,000