Note 6 - Discontinued Operations (Details Textual) - Broadcast Microwave Services, Inc. (“BMS”) [Member] - USD ($) $ in Millions	1 Months Ended
Jun. 30, 2015	Mar. 25, 2017
Proceeds from Divestiture of Businesses	$ 4.9
Disposal Group, Including Discontinued Operation, Contingent Consideration	$ 2.5
Contingent Consideration Receivable, Fair Value		$ 0.3

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromDivestitureOfBusinesses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration