Note 4 - Loans and Allowance for Loan Losses (Detail) - Risk Category of Commercial Loans (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Commercial real estate:
Commercial Loans	$ 230,450	$ 232,249
Pass [Member] | Owner Occupied [Member]
Commercial real estate:
Commercial Loans	91,287	87,614
Pass [Member] | Nonowner Occupied [Member]
Commercial real estate:
Commercial Loans	42,990	39,627
Pass [Member] | Construction [Member]
Commercial real estate:
Commercial Loans	18,200	16,276
Pass [Member] | Commercial and Industrial [Member]
Commercial real estate:
Commercial Loans	49,336	47,226
Pass [Member]
Commercial real estate:
Commercial Loans	201,813	190,743
Criticized [Member] | Owner Occupied [Member]
Commercial real estate:
Commercial Loans	7,803	14,057
Criticized [Member] | Nonowner Occupied [Member]
Commercial real estate:
Commercial Loans	680	2,171
Criticized [Member] | Commercial and Industrial [Member]
Commercial real estate:
Commercial Loans	5,105	4,793
Criticized [Member]
Commercial real estate:
Commercial Loans	13,588	21,021
Classified [Member] | Owner Occupied [Member]
Commercial real estate:
Commercial Loans	3,026	3,171
Classified [Member] | Nonowner Occupied [Member]
Commercial real estate:
Commercial Loans	7,209	10,994
Classified [Member] | Construction [Member]
Commercial real estate:
Commercial Loans	1,070	1,100
Classified [Member] | Commercial and Industrial [Member]
Commercial real estate:
Commercial Loans	3,744	5,220
Classified [Member]
Commercial real estate:
Commercial Loans	15,049	20,485
Owner Occupied [Member]
Commercial real estate:
Commercial Loans	102,116	104,842
Nonowner Occupied [Member]
Commercial real estate:
Commercial Loans	50,879	52,792
Construction [Member]
Commercial real estate:
Commercial Loans	19,270	17,376
Commercial and Industrial [Member]
Commercial real estate:
Commercial Loans	$ 58,185	$ 57,239