Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (6) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013 Factor Market Loan	Jun. 30, 2012	Jun. 30, 2013 Scale Factor Market Loan	Jun. 30, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period			$ 78,738,000
Provision for loan losses, LHFI	(4,846,000)	650,000	(7,814,000)	3,943,000
Balance at end of period	72,825,000		72,825,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Total	72,825,000		72,825,000
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			(6,356,000)	(14,640,000)
Recoveries			8,257,000	5,988,000
Net recoveries (charge-offs)			1,901,000	(8,652,000)
Provision for loan losses, LHFI			(7,814,000)	3,943,000
Balance at end of period	72,825,000	84,809,000	72,825,000	84,809,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	10,690,000	13,769,000	10,690,000	13,769,000
Collectively	62,135,000	71,040,000	62,135,000	71,040,000
Total	72,825,000	84,809,000	72,825,000	84,809,000
Real Estate Secured Financing Receivable [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			(412,000)	(2,765,000)
Recoveries			1,462,000	0
Provision for loan losses, LHFI			(6,424,000)	(190,000)
Balance at end of period	16,464,000	24,265,000	16,464,000	24,265,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	1,527,000	4,830,000	1,527,000	4,830,000
Collectively	14,937,000	19,435,000	14,937,000	19,435,000
Total	16,464,000	24,265,000	16,464,000	24,265,000
Real Estate Secured Financing Receivable [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			(532,000)	(2,578,000)
Recoveries			213,000	252,000
Provision for loan losses, LHFI			(2,697,000)	2,567,000
Balance at end of period	9,941,000	12,891,000	9,941,000	12,891,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	583,000	1,270,000	583,000	1,270,000
Collectively	9,358,000	11,621,000	9,358,000	11,621,000
Total	9,941,000	12,891,000	9,941,000	12,891,000
Real Estate Secured Financing Receivable [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			(434,000)	(2,867,000)
Recoveries			26,000	0
Provision for loan losses, LHFI			(996,000)	3,253,000
Balance at end of period	19,692,000	24,744,000	19,692,000	24,744,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	1,936,000	5,997,000	1,936,000	5,997,000
Collectively	17,756,000	18,747,000	17,756,000	18,747,000
Total	19,692,000	24,744,000	19,692,000	24,744,000
Real Estate Secured Financing Receivable [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			(891,000)	(1,602,000)
Recoveries			30,000	0
Provision for loan losses, LHFI			240,000	225,000
Balance at end of period	1,576,000	1,702,000	1,576,000	1,702,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	38,000	389,000	38,000	389,000
Collectively	1,538,000	1,313,000	1,538,000	1,313,000
Total	1,576,000	1,702,000	1,576,000	1,702,000
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			(658,000)	(514,000)
Recoveries			2,135,000	1,058,000
Provision for loan losses, LHFI			1,755,000	(552,000)
Balance at end of period	17,551,000	15,860,000	17,551,000	15,860,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	6,273,000	1,234,000	6,273,000	1,234,000
Collectively	11,278,000	14,626,000	11,278,000	14,626,000
Total	17,551,000	15,860,000	17,551,000	15,860,000
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			(1,139,000)	(1,644,000)
Recoveries			2,505,000	2,856,000
Provision for loan losses, LHFI			(1,602,000)	(1,883,000)
Balance at end of period	2,851,000	2,985,000	2,851,000	2,985,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	2,000	5,000	2,000	5,000
Collectively	2,849,000	2,980,000	2,849,000	2,980,000
Total	2,851,000	2,985,000	2,851,000	2,985,000
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			(2,290,000)	(2,670,000)
Recoveries			1,886,000	1,822,000
Provision for loan losses, LHFI			1,910,000	523,000
Balance at end of period	4,750,000	2,362,000	4,750,000	2,362,000
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	331,000	44,000	331,000	44,000
Collectively	4,419,000	2,318,000	4,419,000	2,318,000
Total	$ 4,750,000	$ 2,362,000	$ 4,750,000	$ 2,362,000