Note 5 - Loans Held for Investment (Detail) - Mortgage and Lease Receivable Credit Exposure By Internally Assigned Grade (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Residential Real Estate Loans [Member] | Pass [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	$ 68,350	$ 71,491
Residential Real Estate Loans [Member] | Watch [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	758	785
Residential Real Estate Loans [Member] | Special Mention [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	216	229
Residential Real Estate Loans [Member] | Substandard [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	2,259	0
Residential Real Estate Loans [Member] | Doubtful [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Real Estate Loans [Member] | Loss [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Real Estate Loans [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	71,583	72,505
Residential Construction [Member] | Pass [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	2,215	2,834
Residential Construction [Member] | Special Mention [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Construction [Member] | Substandard [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Construction [Member] | Doubtful [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Construction [Member] | Loss [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Construction [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	2,215	2,834
Residential Lots and Raw Land [Member] | Pass [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	929	885
Residential Lots and Raw Land [Member] | Special Mention [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Lots and Raw Land [Member] | Substandard [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Lots and Raw Land [Member] | Doubtful [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Lots and Raw Land [Member] | Loss [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Residential Lots and Raw Land [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	929	885
Mortgage and Lease Receivables [Member] | Pass [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	5,838	5,694
Mortgage and Lease Receivables [Member] | Special Mention [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	86	18
Mortgage and Lease Receivables [Member] | Substandard [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade		0
Mortgage and Lease Receivables [Member] | Doubtful [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Mortgage and Lease Receivables [Member] | Loss [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	0	0
Mortgage and Lease Receivables [Member]
Mortgage and Lease Receivable Credit Exposure by Internally Assigned Grade	$ 5,924	$ 5,712