Note 7 - Commitments and Contingencies (Details Textual) $ in Millions	Jan. 27, 2018 USD ($)
Leveraged Leases, Net Investment in Leveraged Leases Disclosure, Residual Value of Leased Assets	$ 1.6

The estimate of the value of the leased asset at the end of the lease term.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=77895730&loc=d3e42840-112730

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