Note 8 - Fair Value Measurements - Impaired Loans and Other Real Estate Owned Measured at Fair Value on Nonrecurring Basis (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Inputs, Level 1 [Member]
Impaired loans net of valuation allowance	$ 0
Other real estate owned net of valuation allowance	0	0
Fair Value, Inputs, Level 2 [Member]
Impaired loans net of valuation allowance	0
Other real estate owned net of valuation allowance	0	0
Fair Value, Inputs, Level 3 [Member]
Impaired loans net of valuation allowance	1,727,000	2,328,000
Other real estate owned net of valuation allowance	3,425,000	4,165,000
Impaired loans net of valuation allowance	1,727,000	2,328,000
Other real estate owned net of valuation allowance	$ 3,425,000	$ 4,165,000