Note 6 - Securities Sold Under Agreements to Repurchase (Details)	3 Months Ended
Mar. 31, 2016
Maximum [Member]
Note 6 - Securities Sold Under Agreements to Repurchase (Details) [Line Items]
Repurchase Agreement Counterparty, Weighted Average Maturity of Agreements	1 year

Weighted average maturity (weighted by amount of the agreement) of repurchase agreements with the counterparty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(1)(i)(B)(iii))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Name:	us-gaap_RepurchaseAgreementCounterpartyWeightedAverageMaturityOfAgreements1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration