Note 4 - Loans and Allowance for Loan Losses (Details Textual) xbrli-pure in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017 USD ($)	Sep. 30, 2016	Sep. 30, 2017 USD ($)	Sep. 30, 2016	Dec. 31, 2016 USD ($)
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	0	0
Troubled Debt Restructurings [Member]
Allowance for Credit Losses, Change in Method of Calculating Impairment	$ 947,843		$ 947,843		$ 329,734

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration