Note 10 - Securities Sold Under Agreements to Repurchase by Contractual Maturity (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
US Treasuries and Government Agencies [Member] | Maturity Overnight and Continuous [Member]
Securities sold under agreements to repurchase	$ 8,351,000	$ 9,072,000
US Treasuries and Government Agencies [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreements to repurchase	0	0
US Treasuries and Government Agencies [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreements to repurchase	0	0
US Treasuries and Government Agencies [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreements to repurchase	0	0
US Treasuries and Government Agencies [Member]
Securities sold under agreements to repurchase	8,351,000	9,072,000
Residential Mortgage Backed Securities [Member] | Maturity Overnight and Continuous [Member]
Securities sold under agreements to repurchase	6,613,000	3,003,000
Residential Mortgage Backed Securities [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreements to repurchase	0	0
Residential Mortgage Backed Securities [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Residential Mortgage Backed Securities [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Residential Mortgage Backed Securities [Member]
Securities sold under agreements to repurchase	6,613,000	3,003,000
Maturity Overnight and Continuous [Member]
Securities sold under agreements to repurchase	14,964,000	12,075,000
Maturity Less than 30 Days [Member]
Securities sold under agreements to repurchase	0	0
Maturity 30 to 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Maturity Greater than 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Securities sold under agreements to repurchase	$ 14,964,000	$ 12,075,000