Note 5 - Loans and Allowance for Loan Losses (Detail) - Consumer Loans By Credit Quality Indicators (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Pass [Member] | Residential Mortgage Loans [Member]
Loans Receivable	$ 177,787	$ 185,686
Pass [Member] | Home Equity Lines of Credit [Member]
Loans Receivable	151,373	158,335
Pass [Member] | Residential Construction [Member]
Loans Receivable	55,039	52,612
Pass [Member] | Other Loans to Individuals [Member]
Loans Receivable	19,704	15,444
Pass [Member] | Total Consumer Loans [Member]
Loans Receivable	403,903	412,077
Special Mention [Member] | Residential Mortgage Loans [Member]
Loans Receivable	837	1,115
Special Mention [Member] | Home Equity Lines of Credit [Member]
Loans Receivable	1,235	2,599
Special Mention [Member] | Residential Construction [Member]
Loans Receivable	0	0
Special Mention [Member] | Other Loans to Individuals [Member]
Loans Receivable	353	78
Special Mention [Member] | Total Consumer Loans [Member]
Loans Receivable	2,425	3,792
Classified [Member] | Residential Mortgage Loans [Member]
Loans Receivable	1,744	1,731
Classified [Member] | Home Equity Lines of Credit [Member]
Loans Receivable	4,194	2,691
Classified [Member] | Residential Construction [Member]
Loans Receivable	166	200
Classified [Member] | Other Loans to Individuals [Member]
Loans Receivable	180	31
Classified [Member] | Total Consumer Loans [Member]
Loans Receivable	6,284	4,653
Total Commercial [Member] | Residential Mortgage Loans [Member]
Loans Receivable	180,368	188,532
Total Commercial [Member] | Home Equity Lines of Credit [Member]
Loans Receivable	156,802	163,625
Total Commercial [Member] | Residential Construction [Member]
Loans Receivable	55,205	52,812
Total Commercial [Member] | Other Loans to Individuals [Member]
Loans Receivable	20,237	15,553
Total Commercial [Member] | Total Consumer Loans [Member]
Loans Receivable	412,612	420,522
Total Consumer Loans [Member]
Loans Receivable	$ 1,329,958	$ 1,357,316