Note 6 - Loans Held for Investment (Details) - Commercial Credit Exposure by Assigned Risk Grade (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Commercial Real Estate Other Receivable [Member] | Above Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	$ 3,280	$ 2,030
Commercial Real Estate Other Receivable [Member] | Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	54,989	53,699
Commercial Real Estate Other Receivable [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	171,674	166,639
Commercial Real Estate Other Receivable [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	15,078	16,117
Commercial Real Estate Other Receivable [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	6,895	7,195
Commercial Real Estate Other Receivable [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	10,005	10,120
Commercial Real Estate Other Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	261,921	255,800
Commercial Real Estate Construction Financing Receivable [Member] | Above Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	907	778
Commercial Real Estate Construction Financing Receivable [Member] | Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	6,478	5,681
Commercial Real Estate Construction Financing Receivable [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	18,062	17,701
Commercial Real Estate Construction Financing Receivable [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	2,329	2,641
Commercial Real Estate Construction Financing Receivable [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	507	515
Commercial Real Estate Construction Financing Receivable [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	103	330
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	28,386	27,646
Commercial Lots and Raw Land [Member] | Above Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	21	24
Commercial Lots and Raw Land [Member] | Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	1,601	1,560
Commercial Lots and Raw Land [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	16,390	16,601
Commercial Lots and Raw Land [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	3,786	3,948
Commercial Lots and Raw Land [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	3,043	3,201
Commercial Lots and Raw Land [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	1,779	2,168
Commercial Lots and Raw Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	26,620	27,502
Commercial and Industrial [Member] | Above Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	1,015	955
Commercial and Industrial [Member] | Average [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	4,173	5,264
Commercial and Industrial [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	21,608	19,562
Commercial and Industrial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	605	458
Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	2,091	2,051
Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	327	89
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial credit exposure by internally assigned grade	$ 29,819	$ 28,379