Note 11 - Securities Sold Under Agreement to Repurchase - Securities Sold Under Agreements to Repurchase by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Securities sold under agreement to repurchase	$ 19,114	$ 12,075
Maturity Overnight and Continuous [Member]
Securities sold under agreement to repurchase	19,114	12,075
Maturity Less than 30 Days [Member]
Securities sold under agreement to repurchase	0	0
Maturity 30 to 90 Days [Member]
Securities sold under agreement to repurchase	0	0
Maturity Greater than 90 Days [Member]
Securities sold under agreement to repurchase	0	0
Municipal Securities [Member]
Securities sold under agreement to repurchase	3,318
Municipal Securities [Member] | Maturity Overnight and Continuous [Member]
Securities sold under agreement to repurchase	3,318
Municipal Securities [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreement to repurchase	0
Municipal Securities [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreement to repurchase	0
Municipal Securities [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreement to repurchase	0
US Treasuries and Government Agencies [Member]
Securities sold under agreement to repurchase		9,072
US Treasuries and Government Agencies [Member] | Maturity Overnight and Continuous [Member]
Securities sold under agreement to repurchase		9,072
US Treasuries and Government Agencies [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreement to repurchase		0
US Treasuries and Government Agencies [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreement to repurchase		0
US Treasuries and Government Agencies [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreement to repurchase		0
Residential Mortgage-backed Securities [Member]
Securities sold under agreement to repurchase	15,796	3,003
Residential Mortgage-backed Securities [Member] | Maturity Overnight and Continuous [Member]
Securities sold under agreement to repurchase	15,796	3,003
Residential Mortgage-backed Securities [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreement to repurchase	0	0
Residential Mortgage-backed Securities [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreement to repurchase	0	0
Residential Mortgage-backed Securities [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreement to repurchase	$ 0	$ 0