Note 2 - Significant Accounting Policies (Details Textual)	3 Months Ended
Sep. 30, 2018
Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life	20 years
Centerpoint [Member]
Equity Method Investment, Ownership Percentage	58.90%

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration