Note 7 - Loans (Detail) (USD $)	12 Months Ended								3 Months Ended							3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Nonaccrual Loans [Member]	Dec. 31, 2012 Nonaccrual Loans [Member]	Mar. 31, 2013 Accruing Troubled Debt Restructuring Member	Dec. 31, 2012 Accruing Troubled Debt Restructuring Member	Mar. 31, 2013 Accruing Troubled Debt Restructuring Member	Dec. 31, 2012 Accruing Troubled Debt Restructuring Member	Mar. 31, 2013 Non Accruing Troubled Debt Restructuring Member	Mar. 31, 2012 Non Accruing Troubled Debt Restructuring Member	Dec. 31, 2012 Non Accruing Troubled Debt Restructuring Member	Mar. 31, 2013 Reduction Of Stated Interest Rate Member Minimum [Member]	Mar. 31, 2013 Reduction Of Stated Interest Rate Member Maximum [Member]	Mar. 31, 2013 Extension of Maturity Date [Member] Minimum [Member]	Mar. 31, 2013 Extension of Maturity Date [Member] Maximum [Member]	Mar. 31, 2013 Land Loan Member	Mar. 31, 2013 Commercial Real Estate Loans [Member]	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2013 Maximum [Member]
Impaired Financing Receivable, Recorded Investment	$ 230,544,000	$ 248,597,000	$ 100,300,000	$ 103,900,000	$ 130,200,000	$ 144,700,000
Percentage Of Charge-Off To Contractual Balances For Impaired Loans	22.10%	23.20%
Troubled Debt Restructurings, Total							130,200,000	144,700,000	49,900,000		47,700,000
Impaired Financing Receivable, Modifications, Related Allowance							4,700,000	1,100,000	7,600,000		7,800,000
Troubled Debt Restructurings Length of Modifications												6 months	12 months	3 years	25 years
Period Loan Is In Payment Default																		60 days	90 days
Financing Receivable Modification Number Of Contracts Defaulted Within 12 Months																1	2
Financing Receivable Modifications Recorded Investment Defaulted Within 12 Months																2,000,000	111,000,000,000
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 0								$ (679,000)	$ (4,018,000)