Note 9 - Securities Sold Under Agreements to Repurchase - Maturity of Short and Long-Term Repurchase Agreements (Details)	Jun. 30, 2016 USD ($)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Maturity Overnight [Member]
Short and long-term purchase agreements	$ 30,180,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Maturity Less than 30 Days [Member]
Short and long-term purchase agreements	1,200,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Maturity 30 to 90 Days [Member]
Short and long-term purchase agreements	0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Maturity 90 Days to One Year [Member]
Short and long-term purchase agreements	457,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Maturity Over One Year to Four Years [Member]
Short and long-term purchase agreements	101,024,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Short and long-term purchase agreements	132,861,000
Maturity Overnight [Member]
Short and long-term purchase agreements	30,180,000
Maturity Less than 30 Days [Member]
Short and long-term purchase agreements	1,200,000
Maturity 30 to 90 Days [Member]
Short and long-term purchase agreements	0
Maturity 90 Days to One Year [Member]
Short and long-term purchase agreements	457,000
Maturity Over One Year to Four Years [Member]
Short and long-term purchase agreements	101,024,000
Short and long-term purchase agreements	$ 132,861,000