Note 3 - Recent Accounting Pronouncements (Details Textual) - Accounting Standards Update 2016-09 [Member] $ in Millions	Jan. 01, 2018 USD ($)
Deferred Tax Assets, Valuation Allowance, Total	$ 1.1
Deferred Tax Assets, Gross, Total	$ 1.1

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

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