Note 7 - Derivatives and Hedging Activities - Summary of Interest Rate Cap Derivatives (Details) - Cash Flow Hedging [Member] - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Interest Rate Cap [Member]
National Amount	$ 30,000,000
Fair value	506,700	$ 576,527
Other Assets [Member] \| Interest Rate Cap 1 [Member]
National Amount	15,000,000
Fair value	190,085	179,939
Other Assets [Member] \| Interest Rate Cap 2 [Member]
National Amount	15,000,000
Fair value	$ 316,615	$ 396,588

Fair value as of the balance sheet date of all interest rate derivative assets designated as cash flow hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959

Name:	us-gaap_InterestRateCashFlowHedgeAssetAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant